[BRO-39] Migrate away from injecting API (Draft example of chrome API)

[Ivan-Mahda]

Example of forwarding requests to walletApi with Proxy

The general concept of this example is quite simple

In api-helper
We need a proxy with an empty object of WalletApi type
new Proxy({} as WalletApi, proxyHandler)
This enables TS annotations

And we can intercept all requests and forward them through the chrome API
With chrome.runtime.sendMessage

In background.js
With chrome.runtime.onMessageExternal listen to this requests

Main difficulty I encountered is the inability to simply import the walletApi.
A new class needs to be created, which in turn requires many additional changes to BW.
In this case, it looks like a lot of risky changes.