Allow data URI's for image sources and font sources

[aptkingston]

Description

This PR fixes some of the CSP schemes to allow local data: URI's. These were lacking the colon suffix which meant images using data URI's (and fonts, but don't think they're used) would not work.

Fixes #5127.

[shogunpurple]

LGTM!

[shogunpurple]

Been thinking we should probably just open it up a bit for fonts as well - possibly just allow all

[codecov-commenter]

Codecov Report

Merging #5131 (334e416) into master (fc00192) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #5131   +/-   ##
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  Coverage   68.75%   68.75%           
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  Files         146      146           
  Lines        5054     5054           
  Branches      773      773           
=======================================
  Hits         3475     3475           
  Misses       1121     1121           
  Partials      458      458           

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[aptkingston]

You say that but I do remember really old exploits with certain TTFs on windows haha. So it's not 100% safe. But in practice yea, I think that would also be a good idea.