Gravity update: Handle color escape sequences

[catch-error]

What does this PR aim to accomplish?:

Currently when running gravity update, the color escape sequences used by the shell script are printed literally on the web gui:

  [�[1;32m✓�[0m] DNS resolution is available

  [i] Neutrino emissions detected�[0m...
  [�[1;32m✓�[0m] Pulling blocklist source list into range
  ...

This should be the matching real colors instead.

How does this PR accomplish the above?:

The patch checks each line fragment for the existance of a pattern that represents an (ANSI) color code escape sequence and substitutes it with a fitting HTML code.

To preserve color coding also when removing line(s) because of OVER escape sequences, the code is changed from using .text() to .html().

Link documentation PRs if any are needed to support this PR:

N/A

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[yubiuser]

Interesting, what browser do you use?
I don't see colors, but the escape sequences are printed as they should as symbols.

[rdwebdesign]

I just checked and also don't see color codes.
I think they should be stripped before data is sent to the browser. Actually this is how v5 works.

[catch-error]

I tried it on Chrome & Safari on MacOS, Chrome & Firefox and Windows & Linux. Some subtle differences how the actual escape character is printed, but the rest looks pretty much the same on all systems. I have been working with 6.0 code a lot lately, so maybe screwed something up on my DEV VM.