Log: Improve feature deprecation/removal logs

[KobeArthurScofield]

The default logLevel is warning so normally there are not many people know the features that are deprecating.

This pr does these:

• Changing the feature deprecation warning lo level warning: so normally most people can see the warning, and we can have a good use of it.
• Add feature removal warning: This indicate the feature has been removed, and can be use as a "REMOVE BEFORE FLIGHT" tag so we can remove this warning after a long enough period of time.

这个改动是像原来设计/现在这样放在 features 里面，还是转移到 errors 比较好？

[yuhan6665]

感谢！