😕 Rename confusing table names related to code intel

[varungandhi-src]

1. lsif_indexes - Stores metadata about a code intel index job. (per the current schema docs)
   • Why is this confusing:
     1. We no longer use LSIF
     2. indexes seems to imply that it stores information about an index, which is a different entity from an indexing job (which may or may not produce an index)
   • Alternate name ideas: precise_scip_indexing_jobs (parallel to syntactic_scip_indexing_jobs)