Updates to edit group view

[mhkc]

This PR introduces various refinements to the /groups/edit view.

Including,

• Easier selection of which columns to display
• Improved and condensed layout
• Reordering of DOM elements to improve management when there are multiple samples.

closes #86 #87

[mhkc]

What is the correct way to handle long names?

• Maximum allowed length?
• Truncate names longer than 30 chars?
• Add description field with more lenient word count?

[mhkc]

OKed by Jonas