[ADF-5347] Viewer - Closing PDF before all pages are loaded causes errors

[pionnegru]

Please check if the PR fulfills these requirements

• The commit message follows our guidelines
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

What kind of change does this PR introduce? (check one with "x")

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• Documentation
• Other... Please describe:

What is the current behaviour? (You can also link to an open issue here)
ADF-5347

What is the new behaviour?

Does this PR introduce a breaking change? (check one with "x")

• Yes
• No

If this PR contains a breaking change, please describe the impact and migration path for existing applications: ...

Other information:

[codecov-io]

Codecov Report

Merging #6737 (a9eadfe) into develop (f3c4680) will increase coverage by 0.14%.
The diff coverage is 100.00%.

@@             Coverage Diff             @@
##           develop    #6737      +/-   ##
===========================================
+ Coverage    76.38%   76.52%   +0.14%     
===========================================
  Files          882      873       -9     
  Lines        20061    19801     -260     
  Branches      3988     3921      -67     
===========================================
- Hits         15323    15153     -170     
+ Misses        3518     3443      -75     
+ Partials      1220     1205      -15     

Impacted Files	Coverage Δ
lib/core/viewer/components/pdf-viewer.component.ts	83.97% <100.00%> (+0.55%)	⬆️
lib/core/services/translate-loader.service.ts	66.12% <0.00%> (-9.68%)	⬇️
...filters/components/task-filters-cloud.component.ts	85.71% <0.00%> (-1.33%)	⬇️
...sions/src/lib/services/extension-loader.service.ts
...b/extensions/src/lib/services/extension.service.ts
lib/extensions/src/lib/config/action.extensions.ts
lib/extensions/src/lib/services/rule.service.ts
lib/extensions/src/test.ts
lib/extensions/src/lib/config/extension-utils.ts
...b/extensions/src/lib/evaluators/core.evaluators.ts
... and 3 more

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