78e283e656 [test] move wallet helper functions into test library (Martin Zumsande)
f613e5dfda [test] move mining helper functions into test library (Martin Zumsande)
2cb4e8bdc7 [test] move string helper functions into test library (Martin Zumsande)
Pull request description:
This disbands `test/util.h` and `test/util.cpp` and moves the content into the test utility library recently created in #17542, so that all test utility functions are in one place.
The content of the original files are split into three modules:
1) string helper functions go to `test/util/str`
2) mining helper functions go to the newly created `test/util/mining`
3) wallet helper functions go to the newly created `test/util/wallet`
ACKs for top commit:
MarcoFalke:
ACK 78e283e656🔧
Tree-SHA512: f182a61e86e76c32bcb84e37f44904d3a4a9c5a321f7a8efdda5368a6623cb8b5a5384ec4f96e67f0357b0c22099f6e3ecd0ac4cb467e3fa3f3128f8d36edfb8