feat(core): pdf embed view component

[fundon]

Closes: AF-1445
Upstreams: toeverything/blocksuite#8658, toeverything/blocksuite#8752

What's Changed

• uses IntersectionObserver to determine lazy loading
• adds PDFViewerEmbedded component
• automatically shut down workers when out of view

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[fundon]

• feat(core): pdf viewer supports fit to page #8812
• feat(core): pdf embed view component #8671 👈 (View in Graphite)
• feat(core): pdf preview #8569 : 5 other dependent PRs (#8615 , #8720 , #8764 and 2 others)
• feat: allow peek view to be closed by the caller && bump bs #8542
• canary

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[codecov]

Codecov Report

Attention: Patch coverage is 21.42857% with 22 lines in your changes missing coverage. Please review.

Project coverage is 65.71%. Comparing base (1514e12) to head (bec5e53).
Report is 4 commits behind head on canary.

Files with missing lines	Patch %	Lines
...ontend/component/src/utils/observe-intersection.ts	21.42%	21 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           canary    #8671      +/-   ##
==========================================
- Coverage   65.74%   65.71%   -0.03%     
==========================================
  Files         706      709       +3     
  Lines       40541    40578      +37     
  Branches     3898     3906       +8     
==========================================
+ Hits        26652    26665      +13     
- Misses      13473    13496      +23     
- Partials      416      417       +1     

Flag	Coverage Δ
server-test	77.65% <ø> (+<0.01%)	⬆️
unittest	36.08% <21.42%> (-0.02%)	⬇️

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