Permission requests for File System Access API

File System Access API is not fully supported. Works when opening files at https://www.photopea.com/ and we also have not working examples (e.g. saving files at https://whatpwacando.today/audio-recording ). Permission request should be emitted in both cases for security reasons.

The request API is more complex than other permission APIs. It should contain:

• Origin
• Requested file path
• Handle type (file or directory)
• Access type (read, write, read/write)
• ... and methods to accept or reject the request.

Some examples to test:

• https://vscode.dev/
• https://whatpwacando.today/audio-recording
• https://whatpwacando.today/file-system