fix(identity): Enable rsa for wasm32 targets

[kirillsurkov]

Description

For now, the rsa feature is not supported on the wasm32 target. However, the ring crate supports wasm32 targets by enabling the wasm32_unknown_unknown_js feature.

Notes & open questions

I know that migrating to the rsa crate is planned, but it is not expected in the near future. These changes allow us to connect to public bootstrap nodes (which use RSA by default) from the browser.

Change checklist

• [x] I have performed a self-review of my own code
• [ ] I have made corresponding changes to the documentation
• [ ] I have added tests that prove my fix is effective or that my feature works
• [x] A changelog entry has been made in the appropriate crates

[dariusc93]

Also an fyi, no need to rebase the PR :)

[elenaf9]

I think we can just merge master into this branch once, before merging the whole PR. Otherwise everyone who subscribed gets a GitHub notification every single time the master is merged :)