CS-12: CachesReturnValue plugin enhancements

[marian13]

What was done as a part of this PR?

• Used a scope [:return_values] for internals.cache in the CachesReturnValue plugin.
• Extracted hash-based cache implementation into Support.
• Some specs for the wrap_method RSpec helper.
• Added new tasks in ROADMAP.
• More YARD signatures.
• Ability to reset wrapped_method state.

Why it was done?

• The possibility of cache accidental cache collisions is decreased.

How to test?

• Development: Local Development#tests.

Notes

• Initialed developed as a part of CS-11: Add a plugin to cache repeated results #16

Checklist:

• I have performed a self-review of my code
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

[coveralls]

Pull Request Test Coverage Report for Build 3421500893

• 66 of 66 (100.0%) changed or added relevant lines in 8 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.04%) to 95.902%

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Totals
Change from base Build 3415005655:	0.04%
Covered Lines:	5336
Relevant Lines:	5564

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💛 - Coveralls