Follow-up from "Fixed MR list layout on mobile" - Migration to Tailwind

The following discussions from !150087 (merged) should be addressed:

@pgascouvaillancourt started a discussion:

Let's use proper Tailwind in here 🙌

  .issuable-info-container.gl-flex-col.md:gl-flex-row.gl-gap-3
    .issuable-main-info{ class: 'gl-mr-0!' }

@pgascouvaillancourt started a discussion:

Tailwind all the way!

          %span.task-status.gl-inline-block.gl-font-sm

@pgascouvaillancourt started a discussion:

        %span.issuable-reference.gl-inline-block

@pgascouvaillancourt started a discussion:
Interestingly, HAML does not support ! in standard class definitions. So in this case, we are not actually applying the !important version of the util, which I guess was the initial intent. I guess was the intention.

That said, it works without it, so we might as well remove the exclamation mark.

Also, Tailwind!
```
        %span.issuable-authored.gl-inline-block.gl-text-gray-500
```

@pgascouvaillancourt started a discussion:

          %span.issuable-milestone.gl-inline-block.gl-truncate.gl-max-w-26.gl-align-bottom

@pgascouvaillancourt started a discussion:

    .gl-font-sm.gl-flex.gl-shrink-0.gl-align-self-start.gl-gap-1.gl-flex-row.gl-justify-between.gl-w-full.md:gl-w-auto{ class: '!md:gl-flex-col' }

@pgascouvaillancourt started a discussion:

      %ul.controls.gl-gap-3.gl-pl-0.gl-self-end

@pgascouvaillancourt started a discussion:

          %li.gl-flex{ class: '!gl-mr-0' }

@pgascouvaillancourt started a discussion:

          %li.gl-flex{ class: '!gl-mr-0!' }

@pgascouvaillancourt started a discussion:

          %li.issuable-pipeline-broken.gl-flex{ class: '!gl-mr-0' }

@pgascouvaillancourt started a discussion:

        .issuable-updated-at.gl-self-end.gl-hidden.sm:gl-inline-block.gl-text-gray-500

@pgascouvaillancourt started a discussion:

  %li.gl-block.has-tooltip{ title: _('Related merge requests'), data: { testid: 'merge-requests' }, class: '!gl-mr-0' }

@pgascouvaillancourt started a discussion:

  %li.gl-block.has-tooltip{ title: _('Comments'), data: { testid: 'issuable-comments' }, class: '!gl-mr-0' }

@pgascouvaillancourt started a discussion:

  %li.gl-block.has-tooltip{ title: _('Upvotes'), data: { testid: 'issuable-upvotes' }, class: '!gl-mr-0' }

@pgascouvaillancourt started a discussion:

  %li.gl-block.has-tooltip{ title: _('Downvotes'), data: { testid: 'issuable-downvotes' }, class: '!gl-mr-0' }

@pgascouvaillancourt started a discussion:

  %li.issuable-pipeline-status.gl-flex
    = render 'ci/status/icon', status: merge_request.head_pipeline.detailed_status(current_user), option_css_classes: 'gl-flex'