[FEATURE] Make the SDK version programmatically accessible

[dillitz]

Problem Statement
There currently is no way to access the SDK version programmatically.
If you want to check what version is used at runtime you have to pull the version out of the UserAgent string.

Proposed Solution
Introduce a way to access the SDK version.

[nfx]

@Tanmay, can pull request the change? Please introduce the Version class with the single public constant field and refactor the UserAgent class. You also have to modify the .codegen.json to re-point version bump to a new file