Cache the command lines provider to avoid allocation

[MarcoRossignoli]

During the command line validation here https://github.com/microsoft/testfx/blob/main/src/Platform/Microsoft.Testing.Platform/CommandLine/CommandLineHandler.cs#L55 we're "getting" the options more than one time and we don't own all the command line implementations.
This means that we could allocate more time the options array per command line provider.
We should have a thin layer on the real provider to cache at the first usage and avoid the per check allocations.

AB#2016216

[testplatform-bot]

✅ Successfully linked to Azure Boards work item(s):

• User Story 2016216