Accessibility: Form elements in bp-xprofile/

[mercime]

Issues for xProfile fields from #6532

[DJPaul]

Can you add more detail to this please Mercime?

[mercime]

In 10282:

xProfile: Add id for Profile default visibility select field.

See #6655.

[mercime]

In 10298:

xProfile: Add label for multiselectbox field in wp-admin.

See #6655.

[mercime]

In 10299:

xProfile: Add label for number field in wp-admin.

See #6655.

[mercime]

In 10300:

xProfile: Add label for selectbox fields in wp-admin.

See #6655.

[mercime]

In 10301:

xProfile: Add label for textbox fields in wp-admin.

See #6655.

[mercime]

In 10302:

xProfile: Add label for url fields in wp-admin.

See #6655.

[djpaul]

In 10305:

xProfile: adjust wp-admin field labels

The admin_field_html method is only used inside wp-admin, so there's
no need to wrap these template bits inside is_admin checks.

Partially reverts the changes in r10298:10302. See #6655

[mercime]

In 10311:

xProfile: Add labels for datebox field types in wp-admin.

See #6655.

[mercime]

In 10312:

xProfile: Add labels for fields generated when adding options.

A11y fix for each text and checkbox field created for the
multiselect box and checkbox field types which support multiple
default options.

See #6655.

[mercime]

In 10313:

xProfile: Add 'for' attributes for Member Type checkboxes.

Fixes #6655.