build: Follow the new meson porting guidelines

Following the new meson porting guidelines, this patch renames the
build options. The list of changes is as follows:

- Remove the enable prefix from boolean options.
- The character separator from multi-word options has been changed
  to underscore.

The warning compiler options are also removed because meson's
compiler related options should be used.

https://bugzilla.gnome.org/show_bug.cgi?id=788796