remove make_source_manifest in favor of Manifest class

[mslynch]

I noticed there was a lot of code shared between Manifest and make_source_manifest. These changes are going to be useful for an upcoming PR for some Posit Cloud changes.

[github-actions[bot]]

☂️ Python Coverage

current status: ✅

Overall Coverage

Lines	Covered	Coverage	Threshold	Status
4256	2754	65%	0%	🟢

New Files

No new covered files...

Modified Files

File	Coverage	Status
rsconnect/actions.py	33%	🟢
rsconnect/api.py	68%	🟢
rsconnect/bundle.py	80%	🟢
rsconnect/main.py	55%	🟢
TOTAL	59%	🟢

updated for commit: 0aab0b3 by action🐍