chore: added vitest for node and browser testing in abstrations

[musale]

This is a small change that is part of a bigger goal to improve our confidence in browser testing and update the codebase to adapt to node/browser environment without throwing errors:

• adds vitest as the test framework that has browser testing
• drops karma. eventually drop add-ins like sinon used for mocking and completely build on vitest.
• updates test imports to use vitest api
• adds browser testing for the package's abstractions and authentication/azure
• adds utility function to check the environment(node/browser) the code is running in
• Fixes browser incompatible code in authentication.azure package (part of Polymorphism of buffer usage #1072). Should update for the rest of the other instances.

Status

The work in this pr is only done on 2 packages, abstractions and authentication/azure. This should give a basis and open discussion of what the end result for the goals above should look like.

• abstractions package is updated to vitest and has browser tests
• authentication/azure package is updated to vitest and has a trigger for browser tests that pass
• authentication/spfx is not updated
• http is not updated.
• serialization/* is not updated.

[baywet]

this long overdue and great work! thanks for taking care of it!

[musale]

closing in favour of #1102