Add redis ClientManager interface to enable redis database number cus…

[WqyJh]

Refactor the getClient(r *Redis) function to interface, thereby enabling users to customize the creation of the go-redis instance. This approach will indirectly support the selection of Redis numbers, addressing the specific requirements of certain users. Notably, we will not alter RedisConf to avoid potential abuse of the database number, which is considered bad practice.

[codecov]

Codecov Report

Attention: Patch coverage is 87.50000% with 3 lines in your changes missing coverage. Please review.

Project coverage is 90.30%. Comparing base (0443464) to head (b960702).
Report is 656 commits behind head on master.

Files with missing lines	Patch %	Lines
core/stores/redis/redis.go	81.25%	2 Missing and 1 partial ⚠️

Additional details and impacted files

Files with missing lines	Coverage Δ
core/stores/redis/conf.go	100.00% <ø> (ø)
core/stores/redis/redisclientmanager.go	89.28% <100.00%> (+2.32%)	⬆️
core/stores/redis/redis.go	98.69% <81.25%> (-0.18%)	⬇️

... and 2 files with indirect coverage changes

[WqyJh]

Related #1601, #1779, #1779

[WqyJh]

Here is a list of issues and PRs related to the support of redis database selection, highlighting the strong demand for this feature within the community. The absence of this capability places a heavy burden on individuals who require it, as they are forced to maintain their own go-zero and merge pull requests. Therefore, please merge this pull request and provide users with a means to select the database. It is important to note that this proposal does not introduce a Db field in RedisConf directly, thus mitigating the risk of abuse.

• Add prefix for cache keys. #3702
• feat(redis) redis DB property Settings #3132
• How to configure CacheRedis to use Db? #3077
• feat: add redis with db num in node type #2756
• can't set the redis DB number? #2690
• feat: Support redis db selection #2214
• goZero can change Redis database? #1779
• 增加选择redis的数据库的功能 #1601
• redis 怎么配置用哪个DB? #715
• redis db #656
• 关于redis 支持 db选择 #655
• add db to redis conf #644
• 关于自带的redis #472
• redis 支持 select 操作 #368