Fix several issues with generating standalone projects

[seapagan]

Closes the following issues:

• ensure package-mode=false is set for standalone scripts (closes If creating a standalone, poetry install should set 'package-mode=false' in the pyproject.toml #292)
• change the post-process text to reflect whether the project is standalone or not (closes Standalone app should have the ending text changed. #293)
• fix the bad repo suggestion for standalone projects (closes for standalone app, the suggested GitHub URL is wrong, it should be the same as if the app was a package #296)

[codacy-production]

Coverage summary from Codacy

See diff coverage on Codacy

Coverage variation	Diff coverage
✅ -0.09% (target: -1.00%)	✅ 0.00%

Coverage variation details

	Coverable lines	Covered lines	Coverage
Common ancestor commit (edbe1ab)	573	287	50.09%
Head commit (2451973)	574 (+1)	287 (+0)	50.00% (-0.09%)

Coverage variation is the difference between the coverage for the head and common ancestor commits of the pull request branch: <coverage of head commit> - <coverage of common ancestor commit>

Diff coverage details

	Coverable lines	Covered lines	Diff coverage
Pull request (#295)	2	0	0.00%

Diff coverage is the percentage of lines that are covered by tests out of the coverable lines that the pull request added or modified: <covered lines added or modified>/<coverable lines added or modified> * 100%

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