Fix test failure which introduced by #9003.
The following case will occur when querybuf expansion will allocate memory equal to (16*1024)k.
1) make use ```CFLAGS=-DNO_MALLOC_USABLE_SIZE```.
2) ```malloc``` will not allocate more under ```alpine```.

…Followup for #9003) (#9100)

Due to the change in #9003, a long-standing bug was raised under `valgrind`.
This bug can cause the master-slave sync to take a very long time, causing the `pendingquerybuf.tcl` test to fail.
This problem does not only occur in master-slave sync, it is triggered when the big arg is greater than 32k.
step:
```sh
dd if=/dev/zero of=bigfile bs=1M count=32
./src/redis-cli -x hset a a < bigfile
```

1) Make room for querybuf in processMultibulkBuffer, now the alloc of querybuf will be more than 32k.
2) If this happens to trigger the `clientsCronResizeQueryBuffer`, querybuf will be resized to 0.
3) Finally, in readQueryFromClient, we expand the querybuf non-greedily, from 0 to 32k.
    Old code, make room for querybuf is greedy, so it only needs 11 times to expand to 32M(16k*(2^11)),
    but now we need 2048(32*1024/16) times to reach it, due to the slow allocation under valgrind that exposed the problem.

The fix for the excessive shrinking of the query buf to 0, will be handled in #5013 (that other change on it's own can fix failing test too), but the fix in this PR will also fix the failing test.

The fix in this PR will makes the reading in `readQueryFromClient` more aggressive when working on a big arg (so that it is in par with the same code in `processMultibulkBuffer` (i.e. the two calls to `sdsMakeRoomForNonGreedy` should both use the bulk size).
In the code before this fix the one in readQueryFromClient always has `readlen = PROTO_IOBUF_LEN`

The initialize memory of `querybuf` is `PROTO_IOBUF_LEN(1024*16) * 2` (due to sdsMakeRoomFor being greedy), under `jemalloc`, the allocated memory will be 40k.
This will most likely result in the `querybuf` being resized when call `clientsCronResizeQueryBuffer` unless the client requests it fast enough.

Note that this bug existed even before redis#7875, since the condition for resizing includes the sds headers (32k+6).

## Changes
1. Use non-greedy sdsMakeRoomFor when allocating the initial query buffer (of 16k).
1. Also use non-greedy allocation when working with BIG_ARG (we won't use that extra space anyway)
2. in case we did use a greedy allocation, read as much as we can into the buffer we got (including internal frag), to reduce system calls.
3. introduce a dedicated constant for the shrinking (same value as before)
3. Add test for querybuf.
4. improve a maxmemory test by ignoring the effect of replica query buffers (can accumulate many ACKs on slow env)
5. improve a maxmemory by disabling slowlog (it will cause slight memory growth on slow env).

Fix test failure which introduced by redis#9003.
The following case will occur when querybuf expansion will allocate memory equal to (16*1024)k.
1) make use ```CFLAGS=-DNO_MALLOC_USABLE_SIZE```.
2) ```malloc``` will not allocate more under ```alpine```.

…Followup for redis#9003) (redis#9100)

Due to the change in redis#9003, a long-standing bug was raised under `valgrind`.
This bug can cause the master-slave sync to take a very long time, causing the `pendingquerybuf.tcl` test to fail.
This problem does not only occur in master-slave sync, it is triggered when the big arg is greater than 32k.
step:
```sh
dd if=/dev/zero of=bigfile bs=1M count=32
./src/redis-cli -x hset a a < bigfile
```

1) Make room for querybuf in processMultibulkBuffer, now the alloc of querybuf will be more than 32k.
2) If this happens to trigger the `clientsCronResizeQueryBuffer`, querybuf will be resized to 0.
3) Finally, in readQueryFromClient, we expand the querybuf non-greedily, from 0 to 32k.
    Old code, make room for querybuf is greedy, so it only needs 11 times to expand to 32M(16k*(2^11)),
    but now we need 2048(32*1024/16) times to reach it, due to the slow allocation under valgrind that exposed the problem.

The fix for the excessive shrinking of the query buf to 0, will be handled in redis#5013 (that other change on it's own can fix failing test too), but the fix in this PR will also fix the failing test.

The fix in this PR will makes the reading in `readQueryFromClient` more aggressive when working on a big arg (so that it is in par with the same code in `processMultibulkBuffer` (i.e. the two calls to `sdsMakeRoomForNonGreedy` should both use the bulk size).
In the code before this fix the one in readQueryFromClient always has `readlen = PROTO_IOBUF_LEN`

The initialize memory of `querybuf` is `PROTO_IOBUF_LEN(1024*16) * 2` (due to sdsMakeRoomFor being greedy), under `jemalloc`, the allocated memory will be 40k.
This will most likely result in the `querybuf` being resized when call `clientsCronResizeQueryBuffer` unless the client requests it fast enough.

Note that this bug existed even before redis#7875, since the condition for resizing includes the sds headers (32k+6).

1. Use non-greedy sdsMakeRoomFor when allocating the initial query buffer (of 16k).
1. Also use non-greedy allocation when working with BIG_ARG (we won't use that extra space anyway)
2. in case we did use a greedy allocation, read as much as we can into the buffer we got (including internal frag), to reduce system calls.
3. introduce a dedicated constant for the shrinking (same value as before)
3. Add test for querybuf.
4. improve a maxmemory test by ignoring the effect of replica query buffers (can accumulate many ACKs on slow env)
5. improve a maxmemory by disabling slowlog (it will cause slight memory growth on slow env).