dc2fdb99072b87d34620084b82a494a5e698c279 tests: Add fuzzing harness for various CScript related functions (practicalswift)
Pull request description:
Add fuzzing harness for various `CScript` related functions.
**Testing this PR**
Run:
```
$ CC=clang CXX=clang++ ./configure --enable-fuzz --with-sanitizers=address,fuzzer,undefined
$ make
$ src/test/fuzz/script
…
# And to to quickly verify that the relevant code regions are triggered, that the
# fuzzing throughput seems reasonable, etc.
$ contrib/devtools/test_fuzzing_harnesses.sh '^script$'
```
`test_fuzzing_harnesses.sh` can be found in PR #17000.
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Backport of Core PR17083