SPIKE: Extension - Can we derive diversified shielded addresses?

[jurevans]

The SDK currently accepts a diversifier when deriving shielded accounts. The CLI uses this in generating shielded keys, but currently, the extension only creates shielded keys that can be deterministically re-created with the mnemonic seed+zip32 path.

• Look into whether this is even do-able in the extension, and if we would want to
• Look into giving the user the option to diversify their keys
• Also, we still need to look into the flow for generating additional shielded accounts