GeckoVersion raises too many different errors when it can't parse a version

[JohanLorenzo]

This is what GeckoVersion raises:

mozilla-version/mozilla_version/gecko.py

Lines 103 to 109 in ea853e0

	Raises:
	PatternNotMatchedError: if the string doesn't match the pattern of a valid version number
	MissingFieldError: if a mandatory field is missing in the string. Mandatory fields are
	`major_number` and `minor_number`
	ValueError: if an integer can't be cast or is not (strictly) positive
	TooManyTypesError: if the string matches more than 1 `VersionType`
	NoVersionTypeError: if the string matches none.

I initially thought it would be a good idea to have distinct error types, but after years of use, mozilla-version users just would like to know if a version was correctly parsed or not. It would be great to change GeckoVersion (and likely BaseVersion too) to just return a single error type.