Improve unit testing

[HelgeStenstrom]

Description

Improved and more complete unit tests.

StreamPlayerMethodsTest still contains tests that don't pass. The tested methods are candidates for removal from StreamPlayer.

All tests in StreamPlayerMethodsTest must be reviewed: Do they actually verify anything that need to be verified? Or are they too coupled with the current implementation?

StreamPlayerFutureImprovementTest contains tests that currently fail. Failures are caused by behavior in StreamPlayer which I think is wrong or bad. But I may have misinterpreted the intended behavior.

This PR doesn't add any dependencies.

What kind of change does this PR introduce? (check at least one)

• [ ] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [ ] Code style update
• [ ] Refactor
• [ ] Build-related changes
• [ ] This change requires a documentation update
• [x] Other, please describe: Unit tests

Does this PR introduce a breaking change? (check one)

• [ ] Yes
• [x] No

Has This Been Tested?

• [x] Yes
• [ ] No

Checklist:

• [X] My code follows the style guidelines of this project
• [X] I have performed a self-review of my own code
• [X] I have commented my code, particularly in hard-to-understand areas
• [X] I have made corresponding changes to the documentation
• [X] My changes generate no new warnings
• [X] I have added tests that prove my fix is effective or that my feature works
• [X] New and existing unit tests pass locally with my changes
• [X] Any dependent changes have been merged and published in downstream modules

[goxr3plus]

Thank you, i have reviewed your code and merging.

I have seen your other issues i will reply to one by one, it's that i am very busy with the company i am working and i didn't had much time, thank you ♥

[HelgeStenstrom]

Although unit tests are harmless in themselves, this PR needs reviewing.

[goxr3plus]

I had a good look from my mobile on all the 3 files changed, it's just i don't have an option from the app to accept the review code, i can directly merge :)