[QOL] Add OptimizeImplicitlyTriggeredBuild option to disable annoying analyzers

[Xiaoy312]

What would you like to be added:

# OptimizeImplicitlyTriggeredBuild: 
Uncomment this line if you're iterating quickly in your builds. This
will disable most of the C# analyzers, and you'll need to comment that property
before making your pull request.

Why is this needed:

Not wasting time fixing with these while debugging:

• unreachable code
• member was assigned, but never used
• method can be marked static, because it doesnt use any member
• ...

Anything else we need to know?

https://github.com/unoplatform/uno/blob/master/src/crosstargeting_override.props.sample

[Youssef1313]

A better approach here may be to have warnings as errors only in CI.