EZP-31296: As an Editor I want be able to edit custom attributes and styles for links

[SerheyDolgushev]

Question	Answer
Tickets	EZP-31296
Bug fix?	no
New feature?	no
BC breaks?	no
Tests pass?	yes
Doc needed?	no
License	GPL-2.0

There is no UI to edit custom attributes and styles for link elements. Even if you will specify the following configurations:

system:
    default:
        fieldtypes:
            ezrichtext:
                classes:
                    link:
                        choices: [custom-link-1, custom-link-2, custom-link-3]
                        default_value: custom-link-1
                        required: false
                        multiple: false

This PR provides a way to edit custom attributes and classes only for existing links. Please note, it still is impossible to set them when a new link is created. Also, some minor UI fixes might be required here. But it is better to have this option than no option at all.

Checklist:

• Coding standards ($ composer fix-cs)
• Ready for Code Review

[dew326]

Thanks for your contribution.
The code itself looks ok. We need to check with our PMs if we want this feature it that way (I remember we have plans for this), so I summon @SylvainGuittard

[SylvainGuittard]

Thanks @SerheyDolgushev for the contribution.
@dew326 The feature is totally valid. I checked with @inakijv. He worked on some wireframes. He should be able to share them soon.

[SerheyDolgushev]

@SylvainGuittard sorry, any update on this?

[SylvainGuittard]

@SerheyDolgushev Thanks for the reminder, I will come back to you soon.

[ChrisMoutsos]

Sorry, is there any update on this one?

[ChrisMoutsos]

Sorry, forgot to ping @SylvainGuittard