a498acce45 test: MiniWallet: skip mempool check if `mempool_valid=False` (Sebastian Falbesoner)
01552e8f67 test: MiniWallet: always rehash after signing (P2PK mode) (Sebastian Falbesoner)
Pull request description:
MiniWallet's core method for creating txs (`create_self_transfer`) right now always executes the `testmempoolaccept` RPC to check for mempool validity or invalidity. In some test cases where we use MiniWallet to create a huge number of transactions this can lead to performance issues, in particular feature_fee_estimation.py where the execution time after MiniWallet usage (PR #24817) doubled, see https://github.com/bitcoin/bitcoin/issues/24828#issuecomment-1100058100, https://github.com/bitcoin/bitcoin/issues/24828#issuecomment-1100301980. This PR mitigates this by skipping the mempool check if the parameter `mempool_valid` is set to `False`.
As a preparatory commit, the test feature_csv_activation.py has to be adapted w.r.t. to rehashing of transactions, as we now hash all transactions immediately in `create_self_transfer` in order to get the txid (before we relied on the result of `testmempoolaccept`).
On my machine, this decreases the execution time quite noticably:
master branch:
```
$ time ./test/functional/feature_fee_estimation.py
real 3m20.771s
user 2m52.360s
sys 0m39.340s
```
PR branch:
```
$ time ./test/functional/feature_fee_estimation.py
real 2m1.386s
user 1m42.510s
sys 0m22.980s
```
Partly fixes#24828 (hopefully).
ACKs for top commit:
danielabrozzoni:
tACK a498acce45
Tree-SHA512: f20c358ba42b2ded86175f46ff3ff9eaefb84175cbd1c2624f44904c8d8888e67ce64d6dcbb26aabbf07906e6f5bdea40353eba9ae668618cadcfc517ef7201b
d24318a40c