testing: teamcity status reporting from tests has been garbage lately

[knz]

I have processed the queue of TC issues from the last few days and there are a couple entries that are utterly unusable / garbage.

Some examples:

• sqlccl: partitionccl (unknown) failed under stress #27355 https://teamcity.cockroachdb.com/viewLog.html?buildId=771985&tab=buildLog
• github.com/cockroachdb/cockroach/pkg/sql: \x13U��-\x13U�� failed under stress github.com/cockroachdb/cockroach/pkg/sql: \x13U��-\x13U�� failed under stress #27491
• github.com/cockroachdb/cockroach/pkg/storage: {WallTime:1_Logical:0}_writerTS:{WallTime:1_Logical:0}_key:[98]_readerFirst:false_interferes:true} failed under stress github.com/cockroachdb/cockroach/pkg/storage: {WallTime:1_Logical:0}_writerTS:{WallTime:1_Logical:0}_key:[98]_readerFirst:false_interferes:true} failed under stress #27478
• roachtest: fail failed on <unknown branch> roachtest: fail failed on <unknown branch> #27471

Three main problems:

1. the name of the test in the issue title is mangled. Maybe a string escaping problem?
2. the test named in the title has nothing to do with the test that's failing. That's a super-annoying regression from, say, a couple weeks ago. Sometimes the body of the issue with the test details is missing entirely.
3. the build log is usually unreadable because of JSON garbage. Sometimes this JSON is also included verbatim in the body of the github issue. This is hindering my productivity when I am triaging issues.

By scrutinizing the build log sometimes I can determine what is going on better than TC, but even then that is hard (e.g. in the first example above).

cc @benesch @jordanlewis