Inspired by discussion in #31382

Currently, the component specific dashboards of com_menus, com_content, com_users and com_privacy take their dashboard title from a string in com_cpanel.
This makes no sense and is a special threatment of core components which shouldn't happen.

Also current code requires that 3rd party dashboard are named as "com_foo" unlike core dashboards which are just named "foo". This PR will work with both variants for 3rd party.

Summary of Changes

Moving the strings to the correct component language file
Adjusting the title lookup code so it first tries to load the string from a component language file. It prepends the dashboard name with "com_" (eg "content" becomes "com_content) if not already present to guess the related component.
If no string is found it will try with a com_cpanel string.

I removed the string COM_CPANEL_DASHBOARD_CONTENT_WORKFLOW_TITLE="Content Workflow Dashboard" as I couldn't find a workflow related dashboard.

Testing Instructions

Test the various dashboards if the title is still the same.

Actual result BEFORE applying this Pull Request

Titles are shown, but taken from com_cpanel

Expected result AFTER applying this Pull Request

In core all looks fine, titles come from the component language files

Documentation Changes Required

Maybe if dashboard documentation exists somewhere.