Admin forms layout fills screen width

[luistoptal]

Pull request for issue: #2100

IMPORTANT: #2168 extends this PR by updating all the forms to the well layout type. We might merge this PR if we prefer the unwrapped layout or merge #2168 if we prefer the wrapped layout

Unwrapped layout (this PR)

Wrapped layout (#2168)

As per the comments in #2100 the wrapped layout is preferred

Updated all admin forms to make use of a wider region of the page

How to test?

• there are no changes in the html and functionality so all existing tests should pass
• navigate to each admin form (except dataset) and verify layout now fills the horizontal space available

How have functionalities been implemented?

• used different bootstrap classes to use wider responsive layouts
• on mobile, layout becomes a column
• field widths were weighted taking into account visual balance and field type, varying between one, two and three columns, depending on the case
• I opted to add an additional button style to keep button widths more consistant

Any issues with implementation?

there is no way to apply these layout changes consistently while keeping all forms looking great, there are forms with just 2 or 3 fields which leave blank space in the page no matter what layout is adopted

I still think a wide layout looks better generally speaking

Any changes to automated tests?

All existing tests pass