Reuse RepositoryInfo

Currently, the server will always re-analyze the entire repository to gather the RepositoryInfos. If the repository is still on the same Commit as when the last RepositoryInfo was generated, we could simply re-use those for performance reasons.

In a similar fashion, we could re-use SVGs, if they were generated with the exact same filter settings and commit hash, but this seems less likely to generate cache hits.