[FR] Export HTML code to external files and add #NOQA for those

[stroblme]

Is your feature request related to a problem? Please describe.
Currently we get complains by flake that our html code exceeds line length. However, there exist no better way of dealing with this as it is still readable but due to the structure of html naturally gets quite lengthy.

Describe the solution you'd like
Move the layout code to an separate python file and import it in the corresponding page. Then ignore those external files in the flake config, so that we get proper QA for the "functional" code and skip QA for the "structural" one.

Describe alternatives you've considered
Open to other suggestions..

Additional context
N/A

[stroblme]

• requires Adjustable frequencies #44 being merged first, because of potential git conflicts