Style updates

[iammattthomas]

• Plugins — New active/inactive class per discussion with ma.tt; relocating Disable All button to standard .tablenav; Combine Activate/Deactivate and Edit buttons into one cell, separated with a pipe to match actions elsewhere
• Tables — Submit class now has top border to match mockups; equalizing all font sizes per Happy Cog's advice; fixed width TH in form-table so the space between labels and actions are consistent, this matches mockups;
• Layout — Edits to .sidenav and .updated to match current fluid width layout
• Export — Removed .narrow and changed .niceblue table to .form-table

[iammattthomas]

Updates in #6019

[ryan]

(In [7066]) Style updates to plugins, export, and sidemenu from mt. fixes #6019