Issue 7899 dom manipulator

[WavesJ99]

Closes
nasa#7899

Describe your changes: I am working on a team and trying to contribute to this project. This first contribution is supposed to be small and get us used to creating a pr. The change basically decouples the selection.js module with the DOM manipulation. This also makes selction.js adhere to SRP. We understand this is not a significant change but that is exactly what we we were looking for because of the description of our assignment.

All Submissions:

• [Y ] Have you followed the guidelines in our [Contributing document] Yes (I think so)(https://github.com/nasa/openmct/blob/master/CONTRIBUTING.md)?
• [Y ] Have you checked to ensure there aren't other open Pull Requests for the same update/change? Yes
• [N ] Is this a notable change that will require a special callout in the release notes? For example, will this break compatibility with existing APIs or projects that consume these plugins? No

Author Checklist

• [ Y] Changes address original issue?
• [N ] Tests included and/or updated with changes?
• [ Y?] Has this been smoke tested?
• [ N?] Have you associated this PR with a type: label? Note: this is not necessarily the same as the original issue.
• Have you associated a milestone with this PR? Note: leave blank if unsure.
• [ N] Testing instructions included in associated issue OR is this a dependency/testcase change?

Reviewer Checklist

• [Y] Changes appear to address issue?
• [ ?] Reviewer has tested changes by following the provided instructions?
• [ Y] Changes appear not to be breaking changes?
• [ N] Appropriate automated tests included?
• [ Y] Code style and in-line documentation are appropriate?