Enable and enforce Apache Parquet support

Enable and enforce Apache Parquet support for all targets, plus provide tests to verify it is supported:

```cmake
# Additional prerequisites for Apache Parquet
pkg_check_modules(ARROW_GLIB_PARQUET QUIET parquet-glib)
if(FLB_ARROW AND ARROW_GLIB_PARQUET_FOUND)
  FLB_DEFINITION(FLB_HAVE_ARROW_PARQUET)
else()
  message(STATUS "Arrow GLib Parquet not found. Disabling parquet compression")
endif()
```