New Adapter: Microsoft (msft)

[SyntaxNode]

Introduces a new Microsoft adapter with the msft bidder code, complimenting the new Prebid.js adapter of the same name. The bidder params are identical for a more seamless experience.

I discovered some flaws in the json test framework while writing new tests for the Microsoft adapter. Specifically:

• There are no tests for response currency, despite the field being present in tests.
• There are no checks for 1:1 comparisons with multi-request test validation.

Both of these issues are also addressed in this PR, making it a bit long, but a lot more accurate and reliable.