Migrate redux reducer about common

[Davidace136]

변경 사항:

• reducers/common 폴더 하위 js 파일들에 대해 ts로 변경

진행 상황:

• 코드 수정
• 테스팅

특이 사항:

• track.js를 track.ts로 수정 중에 actions/common/track.ts 안에 있는 TracksProps를 사용하는 것이 알맞아 보여 원래 export 되지 않았던 TracksProps를 export 했습니다.

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 35 lines in your changes are missing coverage. Please review.

Project coverage is 4.49%. Comparing base (316d614) to head (6250578).
Report is 16 commits behind head on migration.

❗ Current head 6250578 differs from pull request most recent head 6564ebc. Consider uploading reports for the commit 6564ebc to get more accurate results

Files	Patch %	Lines
src/reducers/common/media.ts	0.00%	9 Missing ⚠️
src/reducers/common/semester.ts	0.00%	9 Missing ⚠️
src/reducers/common/track.ts	0.00%	9 Missing ⚠️
src/reducers/common/user.ts	0.00%	7 Missing ⚠️
src/actions/common/track.ts	0.00%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##           migration     #67      +/-   ##
============================================
+ Coverage       4.12%   4.49%   +0.37%     
============================================
  Files            211     210       -1     
  Lines           6547    6517      -30     
  Branches        1686    1639      -47     
============================================
+ Hits             270     293      +23     
+ Misses          6134    6117      -17     
+ Partials         143     107      -36     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[sboh1214]

src/reducers/common/user.ts 에서 UserState의 user initialState를
undefined에서 null로 변경하였습니다.

[sboh1214]

추가로 common reducer들에 대해서 이름이 모두 reducer로 지정되어 있고, default export와 export가 중복 적용되어 있어 수정했습니다 (6564ebc)