feat: add shaka preload

[yakca]

Details

Adds the recent shaka player feature preload to the DOM player engine, used for DASH and non-native HLS. The preload step fetches further media segments, ahead of playback, than a default load resulting in a better transition between media.

Fairly easy win as story objects already contains and loads the next media in the narrative before playback, so preloading is a limited but impactful code change.

Also includes shaka-player version bump to 4.10.8

Ticket / issue URL

Ticket / issue URL: https://jira.dev.bbc.co.uk/browse/PRODTOOLS-4027

PR Checks

(tick as appropriate)

• PR is linked to ticket / issue
• PR title (merged commit message) follows https://www.conventionalcommits.org/en/v1.0.0/ conventions
• PR has the package.json version bumped

[andy-brown]

Tested locally and with our published Insta story - all works fine and see more content preloaded.