Fix: Contrast is too low for searched items

[nlujjawal]

Issue #, if available:

Description of changes:
In CloudEditor Dark Theme whenever a user searches for a term in the editor, the contrast for the searched items is too low which makes it hard to see the active search text and it's nearly impossible to view other searched text as contrast is too low.
So updated the colours for both above mentioned cases.

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Pull Request Checklist:

• No backwards incompatible changes were made to Ace's public interface which is defined through the main typings file (ace.d.ts) and its references:
  • https://github.com/ajaxorg/ace/blob/master/ace.d.ts
  • https://github.com/ajaxorg/ace/blob/master/ace-modes.d.ts
  • https://github.com/ajaxorg/ace/blob/master/ace-extensions.d.ts

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ScreenShot With new changes

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 86.60%. Comparing base (a66f861) to head (626dfea).
Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #5523      +/-   ##
==========================================
+ Coverage   86.57%   86.60%   +0.02%     
==========================================
  Files         588      590       +2     
  Lines       42600    42705     +105     
  Branches     7071     7096      +25     
==========================================
+ Hits        36882    36985     +103     
- Misses       5718     5720       +2     

Flag	Coverage Δ
unittests	86.60% <ø> (+0.02%)	⬆️

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