feature: Improve phone number validator

A number of improvements for the existing phone number type validator

Primarily this change adds logic for the existing variable supported_regions in the validator, this was currently preforming no function at all. If a user supplies a list of two digit phone number regions to the class the validator will now call phonenumbers to check if the parsed number is indeed within one of the regions supplied or else raise a ValidationError. If supported_regions is an empty list (As is now the default), a valid phone number from any region will be accepted.

Additionally, this change:

Removes unused imports and unused Generator type definition
Removes non functional supported_formats variable , these values can be looked up from the phonenumbers library if needed, no need to re-instantiate this here
Removes min_length and max_length parameters, seeing as this is a wrapper around phonenumbers, the resultant string length should be the responsibility for formatting operation from that library.

pydantic / pydantic-extra-types

feature: Improve phone number validator #202

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