feat: independent player blocks

[johnhooks]

There is a power in the player being composed of independent blocks that can be styled independently and nested inside standard layout blocks. This would allow for end users to build a player that is specific to their use case, and also provide the ability to create different players as patterns.

User story

As a knowledgeable block editor user, I want the power to compose an audio player from blocks, so that I can customize the default player to my needs.

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This customization at a block level would be difficult using media-chrome. There is this opposition of the customizability of the block editor and the Web Component backend of media-chrome. The block editor has an expectation to apply custom style classes and CSS by applying them to block, though these do not pass through into the Web Components. At least, not without transforming the default behavior into CSS custom properties.

To provide the maximum power to the knowledgeable block editor user the independent blocks should not rely on media-chrome.

I would hate to lose the power this library brings, though making it mesh will the concepts of the block editor has marginalized its value. If the media-chrome state can be used inside the context of an interactive block would be an interesting idea.

Sub tasks

• feat: player controller block #17
• feat: player play button block #18