video-format: Move Y210 format declaration to avoid ABI break

The Y210 format was added in the middle of the formats enum and list,
introducing an ABI break.

This issue was detected thanks to the gstreamer-rs test harness.
5 jobs for master in 2 minutes and 24 seconds
Status Job ID Name Coverage
  Manifest
passed #44276
manifest

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  Build
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build fedora x86_64

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canceled #44277
build fedora x86_64

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failed #44278
build fedora x86_64

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canceled #44279
build fedora x86_64

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