use watchers and data instead of computed props to memoize results

[indirectlylit]

Summary

Computed props are re-evaluated down the entire chain, whether or not it's necessary. This can be particularly expensive when the prop drives styles or DOM updates.

before	after

Reviewer guidance

make sure responsive behaviors are still working, especially grids

References

• fixes set Vue to 2.5.17 and use watcher-based optimizations on responsive window mixin #4075
• re: computed properties are re-evaluating more often than expected vuejs/vue#8540

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Contributor Checklist

• Contributor has fully tested the PR manually
• PR has the correct target branch and milestone
• PR has 'needs review' or 'work-in-progress' label
• If PR is ready for review, a reviewer has been added. (Don't use 'Assignees')
• If there are any front-end changes, before/after screenshots are included
• If this is an important user-facing change, PR or related issue has a 'changelog' label

Reviewer Checklist

• Automated test coverage is satisfactory
• Reviewer has fully tested the PR manually
• PR has been tested for accessibility regressions
• External dependencies files were updated (yarn and pip)
• Documentation is updated
• Link to diff of internal dependency change is included
• CHANGELOG.rst is updated for high-level changes
• Contributor is in AUTHORS.rst

[codecov]

Codecov Report

Merging #4372 into develop will decrease coverage by <.01%.
The diff coverage is 75%.

@@             Coverage Diff             @@
##           develop    #4372      +/-   ##
===========================================
- Coverage     52.7%   52.69%   -0.01%     
===========================================
  Files          721      721              
  Lines        23189    23191       +2     
  Branches      3158     3158              
===========================================
  Hits         12221    12221              
  Misses       10234    10234              
- Partials       734      736       +2

Impacted Files	Coverage Δ
...src/views/onboarding-forms/FacilityNameTextbox.vue	93.75% <ø> (ø)	⬆️
...olibri/core/assets/src/mixins/responsive-window.js	84.9% <75%> (-5.1%)	⬇️
...libri/core/assets/src/mixins/responsive-element.js	85.71% <0%> (-14.29%)	⬇️
...bri/plugins/learn/assets/src/views/ContentPage.vue	22.05% <0%> (+0.31%)	⬆️
...ts/src/views/ManageContentPage/ChannelListItem.vue	97.87% <0%> (+2.12%)	⬆️

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[jonboiser]

The SetupWizardIndex test is failing because of 'DefaultLanguageForm'. You can stub DefaultLanguageForm in the tests, or figure out what the problem is in DefaultLanguageForm.

[indirectlylit]

thanks for addressing those issues @jonboiser

was there anything else that I should be doing to get this PR in?

[indirectlylit]

thanks!