fix: add extract-template for po-gettext format

[truong-hua]

The previous implemented of lingui extract-template command does not work with po-gettext format because of hard-coded po. This change support any further po-xyz format in the future.

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[codecov]

Codecov Report

Merging #1089 (8e57561) into main (d461695) will decrease coverage by 0.62%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main    #1089      +/-   ##
==========================================
- Coverage   82.91%   82.28%   -0.63%     
==========================================
  Files          54       56       +2     
  Lines        1639     1677      +38     
  Branches      448      458      +10     
==========================================
+ Hits         1359     1380      +21     
- Misses        163      173      +10     
- Partials      117      124       +7     

Impacted Files	Coverage Δ
packages/cli/src/api/catalog.ts	81.48% <100.00%> (-0.09%)	⬇️
packages/cli/src/api/formats/minimal.ts	25.00% <0.00%> (-8.34%)	⬇️
packages/cli/src/api/compile.ts	96.00% <0.00%> (-4.00%)	⬇️
packages/conf/src/index.ts	80.76% <0.00%> (ø)
packages/cli/src/api/formats/index.ts	60.00% <0.00%> (ø)
packages/loader/src/remoteLoader.ts
packages/remote-loader/src/minimalParser.ts	100.00% <0.00%> (ø)
packages/remote-loader/src/index.ts	66.66% <0.00%> (ø)
packages/remote-loader/src/browserCompiler.ts	64.86% <0.00%> (ø)

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[semoal]

LGTM @truong-hua, really appreciated the contribution. Going to merge it right now, once the ci passes. And I'll release a new version tomorrow, I want to improve some usability with the new tool remote-loader.