Migration to styled-components

Here's a list based off @andrewda's list for adding unit tests to the app (https://github.com/gitpoint/git-point/issues/518), feel free to add/remove components if you think it's necessary.

**For newcomers:**
1. Choose the component you want to style
1. Comment here which component you'd like to work on
1. We'll update this list with your name
1. Make sure to include "before" and "after" screenshots in your submitted PR

# Loaders
- [x] LoadingListItem (@machour - #790)
- [x] LoadingMembersList (unclaimed)
- [x] LoadingRepositoryListItem (unclaimed)
- [x] LoadingRepositoryProfile (unclaimed)
- [x] LoadingUserListItem (@machour - #791)
- [x] LoadingModal (@machour - #792)

# Components
- [ ] IssueListItem (@josenaranjo - #578)
- [ ] RepositoryProfile (@shmesa22 - PR Pending)

# Screens

## issue
- [ ] EditIssue (unclaimed)
- [ ] IssueSettings (unclaimed)
- [x] NewIssue (unclaimed)
- [ ] PullMerge (unclaimed)

## repository
- [ ] IssueList (unclaimed)
- [ ] PullDiff (unclaimed)
- [ ] PullList (unclaimed)
- [ ] ReadMe (unclaimed)
- [ ] RepositoryCodeList (unclaimed)
- [ ] RepositoryFile (unclaimed)
- [x] Repository (@machour - #788)

Done:
- [x] Auth (@ZahraTee - #702)
- [x] Login (@machour - #787)
- [x] Notifications (@ZahraTee - #684)
- [x] Organization (@ZahraTee - #682)
- [x] Search (@Arjun-sna - #710)
- [x] User (@ZahraTee - #683)
- [x] Badge (@jpls93 – #535)
- [x] LoadingContainer (@machour - #782)
- [x] CodeLine (@josenaranjo – #561)
- [x] CommentInput (@shmesa22 – #596)
- [x] CommentListItem (@chinesedfan - #723)
- [x] DiffBlocks (@machour – #692)
- [x] EntityInfo (@MrLoh - #558)
- [x] ImageZoom (@MrLoh - #559)
- [x] InlineLabel (@binkpitch – #544)
- [x] IssueDescription (@josenaranjo - #563)
- [x] IssueEventListItem (@josenaranjo - #564)
- [x] LabelButton (@chinesedfan - #727)
- [x] LabelListItem (@pdong – #509)
- [x] Members (@shmesa22 - #606)
- [x] MentionArea (@binkpitch – #553)
- [x] NotificationIcon (@pdong – #510)
- [x] NotificationListItem (@LeoCp - #610)
- [x] ParallaxScroll (@shmesa22 - #607)
- [x] RepositoryListItem (@apoeco - #605)
- [x] RepositorySectionTitle (Useless component, see #730)
- [x] SectionList (@jamesg1 - #608)
- [x] StateBadge (@rkpasia - #715)
- [x] ViewContainer (@pdong – #508)
- [x] UserListItem (@shmesa22 - #601)
- [x] UserProfile (@chinesedfan – #724)
- [x] SearchBarAndroid (can't be migrated)

Commencez par les composants et les écrans encore non cochés listés dans l’issue, puis examinez les entrées de migration terminées pour en vérifier le périmètre et les conventions. Choisissez un composant non attribué, commentez en indiquant votre choix et utilisez l’implémentation existante du composant comme point d’entrée. C’est terminé lorsque le composant est migré et que la pull request inclut des captures d’écran avant-après.

Rédigé par le modèle d'indexation à partir du texte de l'issue.