92d3d691f0 fuzz: Implement G_TEST_GET_FULL_NAME (Hodlinator)
Pull request description:
Catching up to bench & unit tests. Makes for more orderly paths for fuzz tests using `BasicTestingSetup`.
### Before
```
/tmp/test_common bitcoin/0748ae43ef8fa80703bc/regtest/blocks/xor.dat
```
### After
```
/tmp/test_common bitcoin/tx_pool_standard/f18b3744625e0600eb0c/regtest/blocks/xor.dat
```
ACKs for top commit:
kevkevinpal:
ACK [92d3d69](92d3d691f0)
furszy:
utACK 92d3d691f0
tdb3:
ACK 92d3d691f0
dergoegge:
utACK 92d3d691f0
brunoerg:
code review ACK 92d3d691f0
Tree-SHA512: 5e83970b111232adece10f79e3a43d0c3c49ab635763e2a4b420f1336cbb8fee94aab751264ddec01ac8363166636e3b29cfe3b2969fc28c8dd6b31bda351950