Currently src codeintel upload will translate a SCIP file to LSIF prior to upload. It should instead check with the instance to see if it can handle SCIP uploads. This can be done with a HEAD request to the upload endpoint the which will return a new Accept header, preferred; or by version check which will be less future-proof.

Keep the current behavior in place for instances that do not accept SCIP. For instances that do accept SCIP, we need to upload SCIP files as-is, and translate LSIF files to SCIP. @efritz can expose the utility to do this translation as we've already written a working/tested version for oobmigrations on slightly different data.

Follow-up concerns that should be raised and new tickets filed:

• We should only upload SCIP if the instance accepts it (so that we don't break oobmigration concerns).
• There's a few places in src-cli that we try to read the metadata field from the LSIF file. This should be updated to read from the SCIP index as well.