OSMO-5625: OSMO WCAG 2.1 compliance

[patclarknvidia]

Description

Many UI improvements and Accessibility compliance changes.

• [NEW] OSMO-5899: Link to users workflows from submitted by (also wf and task tables)
• Fixes for focus control when closing modals/slideouts and returning to table entries
• Collapsed header on small screens
• Screen-reader fixes for live regions (persistent)
• Support for zoom up to 200%
• Reflow compliance allowing only tables to scroll hor & ver on small screens
• HTML semantics with landmarks, regions, headings and lists
• Fix responsive UI for modals
• Add skip to content
• Collapse menu on small screens
• [NEW] OSMO-5894: Workflow details page for 1 task view

Checklist

• I am familiar with the Contributing Guidelines.
• New or existing tests cover these changes.
• The documentation is up to date with these changes.

I used Evinced, axe DevTools and NVDA screen reader to test the site. These tools cover most of the a11y requirements.