Use revision versioner to allow custom asset versioning

[luceos]

Changes proposed in this pull request:

Allows asset compilation to use a different version hasher implementation. This allows easier implementation of rev-manifest.json storage locations. Eg on our stack if we override where assets are stored, the rev-manifest.json is stored there too (s3). This causes each request to read from the s3 bucket as well. A better location for something like that would be either the settings table or redis. For normal local-file based Flarum instances, the default rev-manifest handler is sufficient.

Reviewers should focus on:

Is this okay?

Confirmed

• Frontend changes: tested on a local Flarum installation.
• Backend changes: tests are green (run composer test).

Required changes:

• Related documentation PR: (Remove if irrelevant)
• Related core extension PRs: (Remove if irrelevant)

[askvortsov1]

Makes sense to me, but unfortunately we still have to stick with PHPDocs for class parameters until we fully drop 7.3.

[askvortsov1]

Convert the property type to a docblock

[luceos]

Habit be bad, will do so asap.

[luceos]

Convert the property type to a docblock

Done, anything else?