CRM-21427 - Add form validation to make it clear we only allow a single website of each type

[eileenmcnaughton]

Overview

The contact edit & inline contact edit silently don't save multiple websites of the same type - this triggers a validation error

Original = #12582
Before

On saving a contact with 2 'Work' websites only one will be retained

After

On saving a contact with 2 'Work' websites a validation error will be triggered

Technical Details

Adds form validation. The original PR made a slight tweak to the BAO which I left out as it felt like a separate thing. Discussion here is best place to find more #12582

Comments

Am treating this as a reviewer's PR & giving merge on pass. Original by @gboudrias had a style error

[civibot]

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[jitendrapurohit]

@eileenmcnaughton @gboudrias Is there any reason of why website is not allowed to behave in the same way like email or phone? Eg.

I can save 2 emails or phones with type = "work". But get this validation error for website.

Also, the "before" statement from the PR description -

On saving a contact with 2 'Work' websites only one will be retained

seems incorrect as when I revert this PR and try to save 2 website with type = work, both of them are saved for the contact.

[eileenmcnaughton]

@jitendrapurohit arg i don't know - I only know it's been a long whackamole over many many versions