Add shared-storage-locks

[ddbeck]

See:

• https://github.com/WICG/shared-storage/blob/main/README.md#locking-for-modifier-methods
• https://issues.chromium.org/issues/373899210
• https://chromestatus.com/feature/5133950203461632

[Elchi3]

The alternative here would be to make a new feature "Web Locks integration with Shared Storage"
https://chromestatus.com/feature/5133950203461632
https://github.com/WICG/shared-storage?tab=readme-ov-file#locking-for-modifier-methods

[ddbeck]

The alternative here would be to make a new feature "Web Locks integration with Shared Storage" https://chromestatus.com/feature/5133950203461632 https://github.com/WICG/shared-storage?tab=readme-ov-file#locking-for-modifier-methods

@Elchi3 thank you! I wasn't aware of this. I've retooled this PR as adding shared-storage-locks. I noted in a comment that there's potentially missing keys in BCD, depending on how thorough you wish to be there. I also updated the PR description with some additional explanatory links. This was a little hard to get my head around. 😅