Support for delete/abort when experiment is stuck in Queued state

Closes #4679

Proposed changes

Running experiments can be stopped now even if stuck in Queued state and then the experiment can be deleted. When there are running experiments, delete option is disabled

When there are no running experiments when stuck in queued state, delete option is enabled

Types of changes

What types of changes does your code introduce to Litmus? Put an x in the boxes that apply

[x] New feature (non-breaking change which adds functionality)
[ ] Bugfix (non-breaking change which fixes an issue)
[ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
[ ] Documentation Update (if none of the other choices applies)

Checklist

Put an x in the boxes that apply. You can also fill these out after creating the PR. If you're unsure about any of them, don't hesitate to ask. We're here to help! This is simply a reminder of what we are going to look for before merging your code.

[ x] I have read the CONTRIBUTING doc
[x ] I have signed the commit for DCO to be passed.
[x ] Lint and unit tests pass locally with my changes
[ ] I have added tests that prove my fix is effective or that my feature works (if appropriate)
[ ] I have added necessary documentation (if appropriate)

Dependency

Please add the links to the dependent PR need to be merged before this (if any).

litmuschaos / litmus