consider failing indexing of a project if history cache creation fails

[vladak]

As raised on #4145 (reply in thread) , if history cache cannot be generated without problem for a repository, it might make sense to fail the indexing of related project. The raionale being if the history cache is incomplete, the overall index will be incomplete, possibly leading to confusing search results.

Notably, FileHistoryCache#finishStore() contains a soft check for total failure to generate history cache however this does not propagate to the 2nd phase of indexing and in the context of this bug it probably should.

Also, #747 is probably a sibling.

If implemented, it might be worth considering adding some --force indexer option to provide a way how to override this.

[vladak]

The --ignoreHistoryCacheFailures option allows for override.