Remove/reduce unnecessary benchmarks

[peterstace]

Description

• Removes BenchmarkWKBParse, which is actually ~70 tests. There is already a BenchmarkUnmarshalWKB in geom/perf_test.go, which not being as comprehensive, will alert developers to unexpected unmarshal performance regressions.

• Alters BenchmarkSetOperation to have 12 sub benchmarks instead of 48. This reduces the granularity of the sizes of inputs tested, but still gives reasonable coverage.

Check List

Have you:

• Added unit tests? N/A

• Add cmprefimpl tests? (if appropriate?) N/A

• Updated release notes? (if appropriate?)

Related Issue

https://github.com/peterstace/simplefeatures/issues/558

[peterstace]

Thanks for reviewing @albertteoh 😁