Feature request: add methods for working with strings (filtering, changing, converting)

[Vasar007]

Is your feature request related to a problem? Please describe.
Need to add methods for working with strings (filtering, changing, converting).

Describe the solution you'd like
I have already written some methods in project AlgorithmAnalysis.

Describe alternatives you've considered
Try to find some other useful methods in the Internet.

Additional context
Do not forget to add tests.