Adds a property to all typescript telemetry events indicating the version of tsserver in the currently running instance of tsserver.

There are two sources of the version of tsserver:

1. the API version: this is the version that the version provider gets from the package.json at the root of the tsserver path.
2. tsserver's reported version: the server returns its internal version string as part of the 'projectInfo' event. This event is only fired by tsserver if it was started with --enableTelemetry, which only occurs if we decided the APIVersion was >=2.0.8. If we could recover the version from the package.json, then tsserver's reported version should match the API Version unless tsserver was overwritten.

Since the tsserver version is already reported (for recent tsserver versions), we could in principle join the session of an event we are interested in, say when a crash or exception occurs in tsserver, to the corresponding projectInfo event and recover the version of tsserver running. However, this has a couple issues:

1. Events with versions are easily filterable/queryable. This is part of why versioning is considered a good practice.
2. If the crash happens before the projectInfo event fires, we get no version info.
3. If tsserver restarts, the version of tsserver running might change. It may be difficult to disambiguate which event corresponds to which instance of tsserver without many joins, yielding a slow query.
4. It is easier to query

Open questions

1. Should there be distinct properties for distinct version sources, or a single property picking the more reliable of the two?

• I'm not strongly partial either way. It is a bit inefficient to include versions that will almost always agree on every event, but may be useful to see both when there is a discrepancy. We could also only tack on a second property when they disagree.

2. Should we reuse the property name version from projectinfo?

• Note that version is a term that could potentially be overloaded. On the other hand, version is already used by the projectInfo event, and we should (and in this implmentation, do) add the same property to every event, including projectInfo. In the PR, the version property we append to every event will coincide exactly with the version from projectInfo.

TODO

• figure out how to annotate the property correctly for GDPR categorization, and validate it.