Add near contract call-function in near-cli-rs grammar, use FastNear RPC

[n13]

What

• quantus near contract call-function as-read-only <CONTRACT> <METHOD> json-args <ARGS> network-config <NET> now
• quantus near contract call-function as-transaction <CONTRACT> <METHOD> json-args <ARGS> prepaid-gas '30 Tgas' attached-deposit '1 yoctoNEAR' sign-as <ACCOUNT> network-config <NET> sign-with-wallet <WALLET> send|display

The grammar is near-cli-rs's own, copied word for word, so a script written for one runs on the other with sign-with-keychain swapped for sign-with-wallet <WALLET>. display prints the decoded transaction and the equivalent near-cli-rs line without loading the wallet or touching the network. Amounts use near-cli's unit strings; sign-with-wallet takes --password-file for scripting.

Any contract method (storage_deposit, ft_transfer_call, Rhea DCL calls, …) is now reachable from an ML-DSA-65 wallet without a dedicated command.

• submit_dao_call generalised to submit_function_call, shared with the DAO commands.
• RPC defaults switched to FastNear (rpc.mainnet.fastnear.com, test.rpc.fastnear.com); rpc.*.near.org is deprecated and rate-limits. network-config / --network also accept an RPC URL.
• README section for the NEAR commands.

Testing

• cargo test --lib near: 29 passed (6 new: sentence parsing, step order enforcement, units incl. zero deposit, near-cli line rendering, JSON validation). Clippy clean.
• Live as-read-only: get_metadata on dclv2.ref-labs.near (mainnet, v2.3.15) and dclv2.ref-dev.testnet (testnet, v2.3.14), ft_metadata via an explicit RPC URL.
• display of a create_pool transaction: decoded args, gas and deposit match the input; printed near-cli-rs line parses in near-cli-rs.
• Error paths ('30' without unit, unknown network, missing wallet) fail before any network I/O.
• Not yet exercised: as-transaction … send on a live network. It reuses the signing and send_tx path the DAO commands already use in production; a testnet run from an ML-DSA-65-controlled account is still to do before relying on it.

[n13]

Superseded: #174/#175 cover arbitrary contract calls via near-cli-rs sign-later + quantus near sign-cold. The FastNear RPC default from this PR moves to its own PR.