Add tests for resolvers without any tests

[pajlada]

Pull request checklist:

• CHANGELOG.md was updated, if applicable

Description

[codecov]

Codecov Report

Merging #296 (9d2f913) into master (f05cba0) will decrease coverage by 28.15%.
The diff coverage is 16.00%.

@@             Coverage Diff             @@
##           master     #296       +/-   ##
===========================================
- Coverage   72.08%   43.93%   -28.16%     
===========================================
  Files          56       96       +40     
  Lines        1673     3041     +1368     
===========================================
+ Hits         1206     1336      +130     
- Misses        447     1684     +1237     
- Partials       20       21        +1     

Impacted Files	Coverage Δ
internal/db/pool.go	0.00% <ø> (ø)
internal/logger/context.go	0.00% <0.00%> (ø)
internal/logger/logger.go	0.00% <ø> (ø)
internal/routes/twitchemotes/set_loader.go	0.00% <0.00%> (ø)
internal/routes/twitchemotes/initialize.go	20.51% <20.51%> (ø)
...nternal/resolvers/livestreamfails/clip_resolver.go	34.78% <0.00%> (ø)
internal/twitchapiclient/client.go	0.00% <0.00%> (ø)
internal/resolvers/discord/initialize.go	100.00% <0.00%> (ø)
internal/resolvers/default/thumbnail_loader.go	0.00% <0.00%> (ø)
... and 33 more

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