[Bug]: Unclear error when source or target branch does not exist (typo)

[cschreib]

Description

If using the --source-branch or --target-branch options and the specified branch does not exist, the error message is vague and does not explain what is wrong.

Steps to reproduce

1. codefox scan --source-branch my-branch --target-branch main where the real branch should have been spelled my_branch and not my-branch.

Expected behavior

An error tells me that the requested source/target branch does not exist.

Actual behavior

Repository is not found or not have change

Environment

• OS: Ubuntu 22.04
• Python version: 3.11
• CodeFox version: 0.4.6
• Provider: N/A
• Model: N/A

Config (optional)

N/A

Additional context

None.