Add population of the service links table

[Sheikah45]

@Brutus5000 let me know if this is how you thought of it.

Dependent on FAForever/db#294

[codecov]

Codecov Report

Merging #536 (a60a737) into develop (b50b71c) will increase coverage by 0.17%.
The diff coverage is 84.61%.

❗ Current head a60a737 differs from pull request most recent head 425dd6c. Consider uploading reports for the commit 425dd6c to get more accurate results

@@              Coverage Diff              @@
##             develop     #536      +/-   ##
=============================================
+ Coverage      75.46%   75.63%   +0.17%     
- Complexity      1144     1155      +11     
=============================================
  Files            242      244       +2     
  Lines           3639     3674      +35     
  Branches         231      232       +1     
=============================================
+ Hits            2746     2779      +33     
- Misses           796      798       +2     
  Partials          97       97              

Impacted Files	Coverage Δ
.../main/java/com/faforever/api/user/UserService.java	90.79% <78.37%> (-0.37%)	⬇️
...ava/com/faforever/api/data/domain/AccountLink.java	100.00% <100.00%> (ø)
...m/faforever/api/data/domain/LinkedServiceType.java	100.00% <100.00%> (ø)
...main/java/com/faforever/api/data/domain/Login.java	85.00% <100.00%> (-0.72%)	⬇️
...n/java/com/faforever/api/voting/VotingService.java	89.09% <100.00%> (+1.81%)	⬆️

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[Brutus5000]

We should not yet remove steamid from the entity and rather mark it as deprecated (and/or populate it with value deprecated) in order to avoid breaking compatibility with other apps (moderator client)

[Sheikah45]

Do you mean just for visibility sake?
Because it wouldn't break the mod client the Id would just be null in the user management view