[BP MB-30207] - [GSI] Error strconv.ParseInt: parsing "9223372036854776000": value out of range

Repro steps:

1. Create a new 5.0 cluster (or upgrade to 5.0 from 4.6) with documents with numbers greater than and less than MaxInt64.
2. Partially upgrade to 5.1.1 with projector still on 5.0 but indexer moved to 5.1.1
3. In this mixed mode setup, create insert/update mutations with numbers > MaxInt64 range. These document mutations encounter an error as they go through FixEncodedInt step which was introduced to fix format error in bug MB-28956. The error causes the mutation to be skipped. The expected behavior is that document gets indexed with loss of precision.

Impact Area for this issue:
1. Projector version is < 5.1.1 and indexer version >= 5.1.1
and
2. Only new mutations coming from projector go through FixEncodedInt
and
3. Numbers beyond MaxInt64 limit fail during ParseInt call in FixEncodedInt and hence mutation gets skipped.