Improve error handling in room stats and attendance

[SamuelWei]

Fixes #1535

Type (Highlight the corresponding type)

• Bugfix
• Feature
• Documentation
• Refactoring (e.g. Style updates, Test implementation, etc.): Error Handling
• Other (please describe):

Checklist

• Code updated to current develop branch head
• Passes CI checks
• Is a part of an issue
• Tests added for the bugfix or newly implemented feature, describe below why if not
• Changelog is updated
• Documentation of code and features exists

Changes

• Improve error handling in room statistics dialog
• Improve error handling in room attendance dialog
• Add happo.io for visual testing

[codecov]

Codecov Report

Attention: Patch coverage is 61.29032% with 12 lines in your changes missing coverage. Please review.

Project coverage is 80.95%. Comparing base (b030a62) to head (98e361e).

Files with missing lines	Patch %	Lines
...s/js/components/RoomTabHistoryAttendanceButton.vue	55.55%	8 Missing ⚠️
...es/js/components/RoomTabHistoryStatisticButton.vue	66.66%	4 Missing ⚠️

Additional details and impacted files

@@              Coverage Diff              @@
##             develop    #1600      +/-   ##
=============================================
- Coverage      81.01%   80.95%   -0.07%     
  Complexity      1340     1340              
=============================================
  Files            361      361              
  Lines           9225     9255      +30     
  Branches         853      861       +8     
=============================================
+ Hits            7474     7492      +18     
- Misses          1751     1763      +12     

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[cypress]

PILOS    Run #1525

Run Properties:   Passed #1525  •  98e361ead9: Improve error handling in room stats and attendance

Project	PILOS
Branch Review	1535-improve-error-handling-in-room-history-components
Run status	Passed #1525
Run duration	05m 01s
Commit	98e361ead9: Improve error handling in room stats and attendance
Committer	Samuel Weirich
View all properties for this run ↗︎

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Test results
Failures	0
Flaky	0
Pending	0
Skipped	0
Passing	238
View all changes introduced in this branch ↗︎