508 compliance for /collections/datasets/publiclist.php

[NikitaSalikov]

Changes Made:

• Added the internationalization for page's breadcrumbs and header
• 508 fixes: Added Doctype and lang attribute

Pull Request Checklist:

• Features and backlog bugs should be merged into the Development branch, NOT master
• [N/A] Hotfixes should be merged into both the Development and master branches (at the same time).
• All new text is preferrably internationalized (i.e., no end-user-visible text is hard-coded on the PHP pages)
• There are no linter errors
• New features have responsive design (i.e., look aesthetically pleasing both full screen and with small or mobile screens)
• Symbiota coding standards have been followed
• [N/A] If any files have been reformatted (e.g., by an autoformatter), the reformat is its own, separate commit in the PR
• Comment which GitHub issue(s), if any does this PR address
• It is the code author's responsibility to merge their own pull request after it has been approved
• If this PR represents a merge into the Development branch, remember to use the squash & merge option
• [N/A] If this PR represents a merge from the Development branch into the master branch, remember to use the merge option
• [N/A] If the dev team has agreed that this PR represents the last PR going into the Development branch before a tagged release (i.e., before an imminent merge into the master branch), make sure to notify the team and lock the Development branch to prevent accidental merges while QA takes place

Thanks for contributing and keeping it clean!

[Atticus29]

Just the one comment. Total Validator Pro is happy. Thanks, Nikita!

[Atticus29]

If this is not used by a lot of different pages, this should probably be in its own translation page.

Since such translation pages doesn't exist already for collections/datasets/publiclist.php, it seems a little silly to create them just for this one.

But. Leaving them in header.en_template.php seems like a bad pattern for us to have in the codebase.

I hate to say it, but let's create the translation files for just this one single translation...

[Atticus29]

New changes LGTM! Thanks!