feat!: add InfoType enum for PostalInfo.info_type

[gibbz00]

From RFC 5733 - EPP Contact Mapping:

"Two elements are provided so that address information can be
provided in both internationalized and localized forms ... If an
internationalized form (type="int") is provided, ... If a localized form
(type="loc") is provided ..."

[djc]

Thanks, this seems nice! I proactively bumped the version to 0.5.0 in #51 because this change is semver-incompatible.

[gibbz00]

thanks ☺️ I try to place a ! after the conventional commit message scope to indicate semver-breaking changes.

[djc]

thanks ☺️ I try to place a ! after the conventional commit message scope to indicate semver-breaking changes.

I'm not that familiar with that standard, so after we've released 0.5.0 please just call it out explicitly in the PR description.