Implement WASM platform layer for SVC

[evdokimovs]

Required for #134

Synopsis

As part of SVC implementation we need to add new WASM methods for Transceiver encoding configuration.

This PR only adds platform code for WASM, but without actually using it. Implementation of interaction based on server events will be implemented in the future PR.

Solution

Implement Transceiver encoding configuration for WASM platform.

Checklist

• Created PR:
  • [x] In draft mode
  • [x] Name contains issue reference
  • [x] Has type and k:: labels applied
  • [x] Has assignee
• Before review:
  • [x] Documentation is updated (if required)
  • [x] Tests are updated (if required)
  • [x] Changes conform code style
  • [x] CHANGELOG entry is added (if required)
  • [x] FCM (final commit message) is posted or updated
  • [x] Draft mode is removed
• [x] Review is completed and changes are approved
  • [x] FCM (final commit message) is approved
• Before merge:
  • [x] Milestone is set
  • [x] PR's name and description are correct and up-to-date
  • [x] All temporary labels are removed

[evdokimovs]

FCM

Implement WASM platform layer for SVC (#170, #134)

Additionally:
- make default `server`, `grpc` and `client` Cargo features of `medea-control-api-proto` crate