Fix irregular whitespace for MetadataRepresentationListComponent

[alexandrevryghem]

Description

Removed the trailing whitespace below the MetadataRepresentationListComponent when the page size is smaller than 10. Also reduced the spacing below the load more/hide last buttons to match the default spacing between item page fields.

Instructions for Reviewers

List of changes in this PR:

• Hide the mt-2 spacing from the load more/hide last buttons when the page size is smaller than 10
• Replaced the float-start & float-end styling on the load more/hide last buttons with flex box with justify-content: between. This will remove the additional spacing generated by the float logic underneath the buttons.
• Made the separator for this item page field configurable as well

Guidance for how to test and review this PR:

• Create a publication with 1 author
  • Verify that the spacing between the authors field & the next field is now the same as the other fields:
    →
• Create a publication with 10+ authors
  • Verify that the spacing between the authors field & the next field is now the same as the other fields:
    →

Checklist

• My PR is created against the main branch of code (unless it is a backport or is fixing an issue specific to an older branch).
• My PR is small in size (e.g. less than 1,000 lines of code, not including comments & specs/tests), or I have provided reasons as to why that's not possible.
• My PR passes ESLint validation using npm run lint
• My PR doesn't introduce circular dependencies (verified via npm run check-circ-deps)
• My PR includes TypeDoc comments for all new (or modified) public methods and classes. It also includes TypeDoc for large or complex private methods.
• My PR passes all specs/tests and includes new/updated specs or tests based on the Code Testing Guide.
• My PR aligns with Accessibility guidelines if it makes changes to the user interface.
• My PR uses i18n (internationalization) keys instead of hardcoded English text, to allow for translations.
• My PR includes details on how to test it. I've provided clear instructions to reviewers on how to successfully test this fix or feature.
• If my PR includes new libraries/dependencies (in package.json), I've made sure their licenses align with the DSpace BSD License based on the Licensing of Contributions documentation.
• If my PR includes new features or configurations, I've provided basic technical documentation in the PR itself.
• If my PR fixes an issue ticket, I've linked them together.

[nathanmlf]

Hey @alexandrevryghem! I've tested it on my side and everything seems to be working as expected. I will attach some screenshots below for comparison:

One author test (Sandbox):

One author test (PR-5665):

Ten authors test (Sandbox):

Ten authors test (PR-5665):

Nice job with the improvement!

[tdonohue]

@alexandrevryghem : I'm finding that this PR fixes some things, but makes other displays slightly worse??

For example, here's what I see for the same Publication on http://sandbox.dspace.org (without this PR), and on my local machine (with this PR) and on my local machine without this PR.

The Sandbox display looks the best. The behavior with this PR looks decent, but doesn't work if an author has an ORCID next to it. If I remove your PR from my local machine, then authors are jumbled (which doesn't look great either). I'm trying to figure out why I'm seeing three different displays, but it must be based on which features are enabled.

Sandbox display: (See https://sandbox.dspace.org/entities/publication/f3edcd34-ed72-43eb-9594-77c206636540)

This PR's display:

My local machine without this PR:

Overall, this PR seems like it's an improvement, but it's a bit buggy if the authors have an ORCID identifier.

Finally, I did want to note that this PR seems to be a fix for #5519 (which is the bug you see in my local display above) and therefore seems to have an overlap with #5540