[ADD] Integrity checks for CSS and JS files

[ppfeufer]

Description

Added

• Integrity checks for CSS and JS files

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality not to work as expected)

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my code
• I have commented on my code, particularly in hard-to-understand areas
• I have checked my code and corrected any misspellings

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 89.32%. Comparing base (50777fd) to head (422ef1d).
Report is 2 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #144   +/-   ##
=======================================
  Coverage   89.32%   89.32%           
=======================================
  Files          10       10           
  Lines         131      131           
  Branches        8        8           
=======================================
  Hits          117      117           
  Misses          9        9           
  Partials        5        5           

---

Continue to review full report in Codecov by Sentry.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 50777fd...422ef1d. Read the comment docs.