[FEATURE] Update pipeline triggers to run unit tests on PR

**Is your feature request related to a problem? Please describe.**
As we are making this solution public we cannot permit unchecked code to be deployed onto any infrastructure as it could become costly. Therefore we do not want to deploy to test on PR but we do want the results of code coverage and unit test success before we merge into main.

**Describe the solution you'd like**
We should trigger the pipeline to run the unit tests and coverage on PR so we get confidence of the quality but not to deploy to any infrastructure without approval.

**Describe alternatives you've considered**
We could just add approval to the deployment to test which would allow us to approve the deployment to staging from the PR allow a full test and then approval for completion of the pull request to trigger the full pipeline for main.

**Additional context**
We want to reduce the amount of effort for all involved while protecting the infrastructure and limiting costs. We have to always be mindful that there could be a threat actor that will exploit any vulnerabilities and misuse the project.