Improve unittest cmake and gitignore

[aaronj0]

Description

General improvements

Type of change

Please tick all options which are relevant.

• Bug fix
• New feature
• Requires documentation updates

[mcbarton]

@aaronj0 @vgvassilev Almost certainly nothing to do with this PR, but any idea why the coverage report comment is not coming up for this PR? I can see from the ci that the repo is created and uploaded. It is appearing on other recent PRs so a little confused.

[vgvassilev]

No clue, maybe some temporary outage?

[aaronj0]

@aaronj0 @vgvassilev Almost certainly nothing to do with this PR, but any idea why the coverage report comment is not coming up for this PR? I can see from the ci that the repo is created and uploaded. It is appearing on other recent PRs so a little confused.

@mcbarton not sure why, I just rebased, lets see if codecov runs now. Otherwise can you take a look at the PR. I have updated the valgrind command since the CppInterOp tests path has been updated