Fix flaky RsSearchTest score parsing for FT.SEARCH results

[mumez]

Problem

CI run 34097596917 failed on Pharo64-12 with:

RsSearchTest>>testSearchWithOptionsSimpleHashes ...assert: (rs result) score > 0

Root cause

Two issues in search result parsing:

1. RsSearchResult>>score: used asInteger — BM25 scores from RediSearch are fractional floats (e.g. 0.287682...). Converting via asInteger truncates to 0, causing score > 0 to fail intermittently depending on how the Redis client returns the value (String vs Float).

2. RsSearchResultSet used fixed-size chunk parsing — With WITHSCORES, WITHPAYLOADS, and WITHSORTKEYS, the reply layout is variable-length (nested content array vs flat field/value pairs). A fixed chunk size of 5 misaligned fields under some reply formats.

Fix

• Parse scores with asNumber to correctly handle fractional BM25 values.
• Replace fixed-size chunking with stream-based result loading that infers field-pair count per document and supports both nested and flat Redis reply layouts.

Testing

Verified locally on Pharo64-11, Pharo64-12, and Pharo64-13:

Executed 349 Tests with 0 Failures and 0 Errors

#testSearchWithOptionsSimpleHashes passes consistently across multiple runs on Pharo64-12 (the CI version that failed).