[6.x] Remove mb-1.5 when no visible content in a Label

[martyf]

When a Field is configured to not show the Display Label, the mb-1.5 is still applied.

This PR only applies the mb-1.5 when the label has visible content.

This is related to #14707, and requires that be resolved to be notice.

[jaygeorge]

@martyf Hey Marty, cheers for the PR.

I checked this branch out but I still see a margin of mb-2 when hiding a display label:

Let me know if I'm missing something! – here's my blueprint

tabs:
  main:
    display: Main
    sections:
      -
        display: Content
        collapsible: true
        fields:
          -
            handle: title
            field:
              type: text
              required: true
              localizable: false
              validate:
                - required
          -
            handle: content
            field:
              type: markdown
              localizable: true
          -
            handle: hello
            field:
              type: text
              display: Hello
              localizable: false
              hide_display: true
  sidebar:
    display: Sidebar
    sections:
      -
        fields:
          -
            handle: slug
            field:
              type: slug
              localizable: true
              validate:
                - 'max:200'
                - 'new \Statamic\Rules\UniqueEntryValue({collection}, {id}, {site})'
                - 'new \Statamic\Rules\UniqueEntryValue({collection}, {id}, {site})'
          -
            handle: date
            field:
              type: date
              required: true
              default: now
              localizable: false
              validate:
                - required
title: Documentation

[martyf]

That's a different issue - see #14707

That is one I tried to fix up, but is deeper than just changing one file (I believe).

The mb-2 and mb-1.5 are both problematic - so while the mb-2 is still there in this branch, it resolves the mb-1.5.