Add TextMatch custom header to other search type custom headers

[DarkMatterV]

Fix TextMatch Option doesn't work when search type is commits topics repositories or issues (#2385)

Fixes: #2385.

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[codecov]

Codecov Report

Merging #2388 (398d048) into master (697804f) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master    #2388   +/-   ##
=======================================
  Coverage   98.06%   98.06%           
=======================================
  Files         119      119           
  Lines       10545    10548    +3     
=======================================
+ Hits        10341    10344    +3     
  Misses        140      140           
  Partials       64       64           

Impacted Files	Coverage Δ
github/search.go	93.61% <100.00%> (+0.13%)	⬆️
github/repos.go	98.66% <0.00%> (+<0.01%)	⬆️

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[gmlewis]

Thank you, @DarkMatterV !
Please make sure to run the modified files through gofmt.
See CONTRIBUTING.md for more details.

[gmlewis]

Thank you, @DarkMatterV !
LGTM.

Awaiting second LGTM from any other contributor to this repo before merging.

[raynigon]

LGTM

[gmlewis]

Thank you, @raynigon !
Merging.