UI and accessibility clean up on dataverse, dataset and file pgs

[mheppler]

What this PR does / why we need it:

Minor UI clean up, and accessibility improvements to dataverse, dataset and file pgs.

Which issue(s) this PR closes:

Ref #6684 Layout and styling of action buttons on the dataset and file page

Special notes for your reviewer:

See following comment below for outline of changes. No new issue created, just piling onto the new button UI issue.

Suggestions on how to test this:

Simple smoke test for account creation, create dataset, publish, download, etc.

Does this PR introduce a user interface change? If mockups are available, please link/include them here:

Minor UI clean and resolving accessibility issues identified in Siteimprove reports.

Is there a release notes update needed for this change?:

N/A

Additional documentation:

N/A

[mheppler]

CONTACT

• contact message textarea title description

LOGIN

• change terms-agreement-block id's to class's on signup/login/password reset to fix "not unique" errors

DATAVERSE

• add margin-bottom to actionButtonBlock to fix spacing between dataverse desc
• add dataverse search input title description
• improve responsive search, advanced search link for small viewports

DATASET

• add "Select Files" aria-label to file table header
• add "File Count" aria-label to file table header
• add "File Actions" aria-label to file table header
• fix spacing between btns in File Action table header
• remove unnecessary link id's from tabular file download citation
• change terms-agreement-block id's to class's on publish popup to fix "not unique" errors
• add file table search input title description
• add deaccession reason textarea title description
• add terms of access input textarea title description
• add return to author reason textarea title description
• fix Terms of Access label for reference to input on download terms popup
• fix Request Access label for reference to input on download terms popup

FILE

• change i component to em for dataset title in file citation
• fix Terms of Access label for reference to input on download terms popup
• fix Request Access label for reference to input on download terms popup

[coveralls]

Coverage remained the same at 19.557% when pulling 18d16f1 on 6684-additional-ui-cleanup into ce86fed on develop.