Proposal: Add first chia wallet address to RPC

[forReason]

Into:

For some bigger exchanges like okx.com or gate.io you can only withdraw chia to a whitelisted adress.
If one wants to make a withdrawal programatically one needs to supply always the same wallet address.

Ideal for this would be the first wallet address, obtainable with chia keys show:

Problem:

Unfortunately the same endpoint (get_public_keys & get_private_keys) does not return this wallet address. The first wallet address is unavailable in RPC.
This means that a address has to be either hardcoded or the management software has to store the adress somewhere in a config file which both is suboptimal for managing larger environments.

Proposal

I propose to add the first wallet address to the RPC interface for several reasons:

• More options to interact with the wallet as stated above
• consistency with the capabilities of the cli interface

The first wallet address can be implemented in different ways:

• like in CLI when calling get_public_keys (for consistency with cli, but I think its inapropriate there)
• in the wallet information when calling get_wallets (probably the cli should also be adapted then to show in chia wallet show)
• As an option or additional parameter in get_next_address eg:

{
    "address": "xch1jxe8yfq8xem0e8ty5dq9hp86ududys96n6ugy2q4fextr0pplw9qwpfru9",
    "root_address": "xch1........."
    "success": true,
    "wallet_id": 2
}

• As a separate request such as get_root_address:

chia rpc wallet get_root_address '{"wallet_id": 2}'

{
    "address": "xch1jxe8yfq8xem0e8ty5dq9hp86ududys96n6ugy2q4fextr0pplw9qwpfru9",
    "success": true,
    "wallet_id": 2
}