[backport#16796] wallet: Fix segfault in CreateWalletFromFile

Summary:
wallet: Fix segmentation fault in CreateWalletFromFile (MarcoFalke)
test: Print both messages on failure in assert_raises_message (MarcoFalke)
wallet: Fix documentation around WalletParameterInteraction (MarcoFalke)

Pull request description:

Comes with a test to aid review. The test should fail without the fix to bitcoind

The following `CreateWalletFromFile` issues are fixed:

* `walletFile` refers to freed memory and will thus corrupt the debug.log and/or crash the node if read
* `WalletParameterInteraction` was moved to `CreateWalletFromFile` and `WalletInit::ParameterInteraction` without updating the documentation

https://github.com/bitcoin/bitcoin/pull/16796/files

Backport of Core PR16796

Test Plan:

ninja check check-functional

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Differential Revision: https://reviews.bitcoinabc.org/D7053