Log pull handler bootstrap failure

[cambot]

This is a follow up to PR #1005 for #1000

Description

• Embedded Git should capture if loading a custom pull event handler fails in a DeploymentLog entry because not every call to ForModifications() displays the return status in the event of an error.
• Refactored: extracted named methods within DeploymentLog to make the flow within ForModifications() a little more human readable and avoid duplicate property sets.
  • Added a Unit Test

Testing

I added a unit test case, but I only have the ability to compile code and run things in terminal. Unfortunately, I am not in a position to fully configure my current Iris instance to run the test suite at the moment.

Checklist

• This branch has the latest changes from the main branch rebased or merged.
• Web UI has been built (any changes in git-webui/src have matching changes in git-webui/release)
• CHANGELOG.md entry added if appropriate.
• Documentation has been/will be updated

[isc-pbarton]

Looks good, merging as is. No changelog needed as this is an improvement to an unreleased feature.