feat: Added Online Read Range functionality for Redis

[Manisha4]

What this PR does / why we need it:

Added Online Read Range functionality for Redis.

The core behavior is:

• Serialize entity keys using the same Python–compatible serialization.
• Group requested features by Feature View.
• Compute ZRANGEBYSCORE bounds from Feast SortKeyFilter rules, supporting equals, inclusive/exclusive ranges, and time.Time values.
• Pipeline ZRANGE calls per entity key across all feature views, retrieving the list of sort keys in the requested range.
• For each returned sort key, pipeline batched HMGET operations, fetching the values and timestamp for each row.
• Decode protobuf feature values and timestamps into RangeFeatureData, preserving order, status, and timestamp.
• Return a matrix of shape [#entity_keys][#requested_features], each containing time-ordered slices of values, statuses, and event timestamps.
• Return the results

Which issue(s) this PR fixes:

Misc

[piket]

Condense to one line

Suggested change

	end := start + PIPELINE_BATCH_SIZE
	if end > len(members) {
	end = len(members)
	}
	end := max(start + PIPELINE_BATCH_SIZE, len(members))

[piket]

Let SortOrder_INVALID be handled by the default. It shouldn't actually come up given our validations.

[piket]

It looks like this is a common function for redis and valkey, it should be moved to the utils file.

[piket]

LGTM