feat: Get author's email token from within KMP when generating a NewUploadSession

[LunarX]

Apps don't need to get the authorEmailToken manually through the emailTokensManager by themselves, the shared KMP code can handle this matter automatically when generating a NewUploadSession.

This PR exposes a new generateNewUploadSession() method that needs to be called to get the NewUploadSession to pass to UploadManager's createAndGetUpload()

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud