feats: extend ValuePool by new fields : files, and maxMutations

[oetr]

1. The users can now supply glob patterns to the @ValuePool annotation by using the new field String[] files---files matching the patterns will be loaded as byte []. The field uses the glob: syntax of java.nio.file.PathMatcher.

Example:

@ValuePool(files={"src/test/resources/**", "/home/user/fuzzing-corpus/compression/zip/**"})

2. In addition, by setting the new field maxMutations, the users can now control up to how many times (by default 1) values selected from @ValuePool will be mutated by the underlying mutator in one mutation operation.