feat: add target filter

[andylokandy]

closes #8

[tisonkun]

@andylokandy this should close #8

I have some questions when considering the design of this filter, you can take a look #8 (comment)

Those can be faq when using this filter.

[andylokandy]

Yes. I'm following the idea in #8.

Q: If multiple LogLevelModuleFilter configured? What's the manner? Especially if the targets are overlapped
A: Simply apply by the filter order

Q: What is the priority between LogLevelModuleFilter and LevelFilter.
A: LogLevelModuleFilter is super set of LevelFilter. LevelFilter is simpler to use.

Q: Filters are applied in order, but when to short circuit the test (by Accepted/Rejected)
A: LevelFilter will reject if level is lower than levelfilter, and LogLevelModuleFilter will reject if level is lower than levelfilter and the target is matched

[tisonkun]

LGTM. One minor comment inline.