Prevents viewer from using the video seekbar to skip questions when skip disabled

[dalmia]

Fixes #628

Summary

• maintaining a variable for the last answered interaction index
• when the video is seeked, if the skip is disabled and there are interactions pending and the timestamp that is being seeked to is greater than the timestamp of the first unanswered interaction index, the viewer is shown that interaction
• when the page is reloaded, if the user was at a timestamp > timestamp of the first unanswered interaction index, we show that interaction.
• if a user clicks on play when on an unanswered question, they are not allowed to move ahead if skip is disabled

Test Plan

• Test Responsiveness
  • Laptop (1200px)
  • Tablet (760px)
  • Phone (320px)
• Cross-Browser Testing
  • Chrome
  • Firefox
  • Safari (use BrowserStack)
• Local Language Support
• Hygiene and Housekeeping
  • Self-review
  • Comments have been added appropriately
  • Check for bundle size here if adding a package
  • Added relevant details like Labels/Projects/Milestones etc.
  • If adding or removing any environment variable:
    • update docs/ENV.md
    • update Github Workflow files
    • update DockerFile
    • update the secrets for staging and production
• Testing
  • Wrote tests
  • Tested locally
  • Tested on staging
  • Tested on an actual physical phone
  • Tested on production
• Lighthouse Checks
  • Images have alt attributes
  • Any <img> tags have width and height specified
  • Any target="_blank" links have rel="noopener"
  • Only SVGs are used as images. If PNGs are used, their size has been optimised.
  • Any SVGs without text have their aria-label attributes set

[codecov]

Codecov Report

Merging #629 (52c06f6) into master (996aaf3) will decrease coverage by 0.94%.
The diff coverage is 31.68%.

@@            Coverage Diff             @@
##           master     #629      +/-   ##
==========================================
- Coverage   85.72%   84.77%   -0.95%     
==========================================
  Files          69       69              
  Lines        4384     4452      +68     
  Branches      782      806      +24     
==========================================
+ Hits         3758     3774      +16     
- Misses        602      654      +52     
  Partials       24       24              

Impacted Files	Coverage Δ
src/pages/Embeds/Plio.vue	58.02% <31.68%> (-6.38%)	⬇️

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