The legacy wallet allowed to import any raw script, without checking if
it was valid or not. Appending it to the watch-only set.

This causes a crash in the migration process because we are only
expecting to find valid scripts inside the legacy spkm.

These stored scripts internally map to `ISMINE_NO` (same as if they
weren't stored at all..).

So we need to check for these special case, and take into account that
the legacy spkm could be storing invalid not watched scripts.

Which, in code words, means IsMineInner() returning IsMineResult::INVALID
for them.

Github-Pull: bitcoin#28125
Rebased-From: 1de8a23

The migration process must skip any invalid script inside the legacy
spkm and all the addressbook records linked to them.

These scripts are not being watched by the current wallet, nor should
be watched by the migrated one.

IsMine() returns ISMINE_NO for them.

Github-Pull: bitcoin#28125
Rebased-From: 8e7e3e6

This reduces chances of having old estimates in fee_estimates.dat.

Github-Pull: bitcoin#27622
Rebased-From: 5b886f2

Old fee estimates could cause transactions to become stuck in the
mempool. This commit prevents the node from using stale estimates
from an old file.

Github-Pull: bitcoin#27622
Rebased-From: 3eb241a

If -acceptstalefeeestimates option is passed stale fee estimates can now
be read when operating in regtest environments.

Additionally, this commit updates all declarations of the CBlockPolicyEstimator
class to include a the second constructor variable.

Github-Pull: bitcoin#27622
Rebased-From: cf219f2

This commit adds tests to ensure that old fee_estimates.dat files
are not read and that fee_estimates are periodically flushed to the
fee_estimates.dat file.

Additionaly it tests the -regtestonly option -acceptstalefeeestimates.

Github-Pull: bitcoin#27622
Rebased-From: d2b39e0

Github-Pull: bitcoin#27834
Rebased-From: fa22538

Loading a wallet with conflicts without a chain (e.g. wallet tool and
migration) would previously result in an assertion due to -1 being both
a valid number of conflict confirmations, and the indicator that that
member has not been set yet.

Github-Pull: bitcoin#28542
Rebased-From: 782701c

By moving the appMenuBar destruction responsibility to the QT
framework, we ensure the disconnection of the submenus signals
prior to the destruction of the main app window.

The standalone menu bar may have served a purpose in earlier
versions when it didn't contain actions that directly open
specific screens within the main application window. However,
at present, all the actions within the appMenuBar lead to the
opening of screens within the main app window. So, the absence
of a main app window makes these actions essentially pointless.

Github-Pull: gui#751
Rebased-From: bae209e

There is no significant benefit in logging the request count instead
of the connection count. Reduces amount of code and computational
complexity.

Github-Pull: bitcoin#28551
Rebased-From: 084d037

It is possible that the client disconnects before the request is
handled. In those cases, evhttp_request_set_on_complete_cb is never
called, which means that on shutdown the server we'll keep waiting
endlessly.

By adding evhttp_connection_set_closecb, libevent automatically
cleans up those dead connections at latest when we shutdown, and
depending on the libevent version already at the moment of remote
client disconnect. In both cases, the bug is fixed.

Github-Pull: bitcoin#28551
Rebased-From: 68f23f5