Merge bitcoin/bitcoin#21359: rpc: include_unsafe option for fundrawtransaction

11d6459b6e rpc: include_unsafe option for fundrawtransaction (t-bast)

Pull request description:

  Allow RPC users to opt-in to unsafe inputs when funding a raw transaction.

  Applications that need to manage a complex RBF flow (such as lightning nodes using anchor outputs) are very limited if they can only use safe inputs.

  I also added this option to `send` and `walletcreatefundedpsbt` who internally delegate to `fundrawtransaction`.

  Fixes #21299

ACKs for top commit:
  laanwj:
    Code review ACK 11d6459b6e

Tree-SHA512: 5e542a4febcfd6f41cf784678ff02ec9282eae2082c274983f72c5ea87b7ebbe1bd5fdc6a020d7a9d5996157754eb4966b8aeb6c1ceebf0b1519f735579b8bac

doc/release-notes.md

@@ -152,6 +152,11 @@ Wallet
 - The `bumpfee` RPC is not available with wallets that have private keys
   disabled. `psbtbumpfee` can be used instead. (#20891)
 
+- The `fundrawtransaction`, `send` and `walletcreatefundedpsbt` RPCs now support an `include_unsafe` option
+  that when `true` allows using unsafe inputs to fund the transaction.
+  Note that the resulting transaction may become invalid if one of the unsafe inputs disappears.
+  If that happens, the transaction must be funded with different inputs and republished. (#21359)
+
 GUI changes
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