Unify `RESERVED_PARAMETER_NAMES` and `GLOBAL_OPTIONS`

[alcuadrado]

We have two ways to define global builtin options. I think we should unify them, so that most of hardhat can treat the same as user-defined global options.

The one exception would be that some of these built-in global options need to be parsed differently, but it's better to contain that in the parser.

See my comment here: #5409

[schaable]

List of changes:

• [x] RESERVED_PARAMETER_NAMES: update this to be a list of reserved words instead of the current list of built-in options. This list is intended to reserve specific words for future use. The built-in options are already validated by TaskManager.#validateClashesWithGlobalOptions.
• [x] GLOBAL_OPTIONS: change this to be an actual array of options, including all their properties, and use globalOption to construct them. Also, rename the variable from GLOBAL_OPTIONS to BUILTIN_OPTIONS, as it only includes the Hardhat built-in options. The logic in v-next/hardhat/src/internal/cli/helpers/utils.ts should be updated to reflect this new format.
• [x] Pass the user-defined global options to getGlobalHelpString and print them along with the built-in options.