ENH: UI enhancements for "Create Task" Tab

[hina-shah]

• Rename "Validate File Selection" on the compute tab to "Create Task" - and as you suggested show the first two tasks
• Make "Preview Task" to "Preview all tasks"
• Put "Create Task", "Preview all tasks", "Run!" at the bottom of the page
• Put "Description" from software definition in place of the "Preview Tasks" button. We can add a full description, like what folders should a user choose, and any other variables that they need to change. The description should also point to the github repository. (Or we can make it part of software definition - but that's later)
• When "Run!" is hit, show a message with "Job ID" and/or "Job Name"
• Rename "Edit values globally for generated tasks" to "Change default parameters for the task"