DATAUP-246: Consolidate css files in static/kbase/css directory

[ialarmedalien]

Description of PR purpose/changes

Renaming and moving the styles from the nbextensions directory into the kbase-extension/static/kbase/css directory to make it easier to reorganise / convert to scss.

advancedViewCell/styles/main.css ==> advancedViewCell.css
editorCell/styles/main.css ==> editorCell.css

Removed css files with no content and an unreferenced file in the editorCell dir.
Edited the corresponding JS files to reference the moved files.

Jira Ticket / Issue

https://kbase-jira.atlassian.net/browse/DATAUP-246

Testing Instructions

• Details for how to test the PR:

• Tests pass in travis and locally
• Changes available by spinning up a local narrative and clicking around to check there are no egregious css horrors (other than any that already exist). Check in the sources (or equivalent for your browser) panel that advancedViewCell.css and editorCell.css are loaded when you open a page.

Dev Checklist:

• My code follows the guidelines at https://sites.google.com/truss.works/kbasetruss/development
• I have performed a self-review of my own code
• My changes generate no new warnings
• New and existing unit tests pass locally with my changes

[coveralls]

Coverage increased (+0.006%) to 16.983% when pulling 57b2cc2 on DATAUP-246_css_to_sass-cell_type_css into 86f459d on truss.

[sonarcloud]

SonarCloud Quality Gate failed.

1 Bug
0 Vulnerabilities (and 0 Security Hotspots to review)
0 Code Smells

No Coverage information
0.0% Duplication

[briehl]

Looks great!