feat: --send-all option

[x100111010]

• added --send-all option to send command, allowing users to send their entire mature balance minus an optional priority fee
• retains feature parity between Go and Rust implementations (the Go wallet has --send-all)
• fix formatting and typos

[x100111010]

I can also confirm that it works, as I've tested it on our testnet:

Test [c500ac46] • 3,587.9997784 TSPR (180 TSPR) $ send spectretest:qpr45ckkggwygdxdg7jxzkqcpd26s7q9rg0mxzncv90wy9hps8e0vhlq4j0dt --send-all
Enter wallet password:
Transaction sent - Amount: 3,587.9997784 TSPR  Fees: 0.00057936 TSPR  Total: 3,588.00035776 TSPR  UTXOs: 51

Sending 3,587.9997784 SPR to spectretest:qpr45ckkggwygdxdg7jxzkqcpd26s7q9rg0mxzncv90wy9hps8e0vhlq4j0dt

With priority fee:

Test [c500ac46] • 228.02882758 TSPR (240 TSPR) $ send spectretest:qpr45ckkggwygdxdg7jxzkqcpd26s7q9rg0mxzncv90wy9hps8e0vhlq4j0dt --send-all 2
Enter wallet password:
Transaction sent - Amount: 226.02882758 TSPR  Fees: 2.0002216 TSPR  Total: 228.02904918 TSPR  UTXOs: 19

Sending 226.02882758 SPR to spectretest:qpr45ckkggwygdxdg7jxzkqcpd26s7q9rg0mxzncv90wy9hps8e0vhlq4j0dt