Add pronouns.page support

[ItsVipra]

Reasoning

Some people only link to pronouns.page for their pronouns.
These instances are currently treated as "no pronouns found" in ProToots.
However pronouns.page does have a public API so adding support for those links wouldn't be too big of an issue.

Implementation idea

When finding a pronouns.page link in a user's field/bio send a GET request to pronouns.page and proceed with the response, as pronouns were found in the field/bio.

[ItsVipra]

Languages

pronouns.page/api/profile/get/{username}?version=2 provides pronouns in every language defined by the user. Displaying all of them is not viable, as that could take up too much space.
Instead I propose we display only two:

• (if available) pronouns matching the browsers language
• english pronouns

In the rare case that English is not available, maybe display just the first language on the profile?

Opinion

pronouns.page also supplies an opinion field with each pronoun. We pay attention to only use pronouns that are actually okay with the pronouns.page owner (okay, yes).

Linking to the page

We can add the pronouns.page icon to the plate so that users can click on it to get to the respective page. We can display this anytime we find a pronouns.page link.
However: If an author also supplies their pronouns outside of pronouns.page we should prefer using those for simplicity.