Allow customising txn confirmation screen based on the txn type

[onyb]

Currently, the ConfirmTransactionPanel is crammed with custom logic for all the different transaction types. The idea is to have dedicated components for each txn type. A good candidate for this is the confirmation screen for swap. The goal of this issue is to refactor ConfirmTransactionPanel to allow rendering a component dedicated to swap when interacting with the 0x Exchange Proxy

Here's an example from Metamask:

Some UX customisation ideas (outside the scope of this issue):

• No need to display the Total.
• Indicate the make and taker assets, along with their quoted amounts.
• Display exchange rate.
• Approve + Swap in batch.
• Fetch the full swap quote in the confirmation screen every 40s, so quote details including order route and liquidity sources are available to be displayed.

[onyb]

Closed in brave/brave-core#14745.