Adding score_cast_func argument to zrank, zrevrank and zunion - for consistency with the other sorted sets commands

[petyaslavova]

Pull Request check-list

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• Do tests and lints pass with this change?
• Do the CI tests pass with this change (enable it first in your forked repo and wait for the github action build to finish)?
• Is the new or changed code fully tested?
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Description of change

This change is adding score_cast_func argument to the commands that had with_score/s argument - this way all commands expose consistent pattern how to handle the responses.

Another change added here is adding the usage of the configured score_cast_func for RESP3 responses as well - with the current code this argument value was completely ignored for resp3 responses.

Fixes #3300

[Copilot]

Pull Request Overview

This PR adds consistency to Redis sorted set commands by adding the score_cast_func parameter to zrank, zrevrank, and zunion commands, aligning them with other sorted set operations. It also ensures that score_cast_func is properly applied to both RESP2 and RESP3 protocol responses.

• Adds score_cast_func parameter to zrank, zrevrank, and zunion commands for consistency
• Introduces new parser helper functions to handle score casting for rank operations in both RESP2 and RESP3
• Updates test cases to verify the new functionality works correctly with custom score cast functions

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
redis/commands/core.py	Adds score_cast_func parameter to zrank, zrevrank, and zunion methods
redis/_parsers/helpers.py	Introduces new parser functions for handling score casting in rank operations for both RESP protocols
tests/test_commands.py	Adds comprehensive test coverage for the new score_cast_func parameter functionality

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