[epic] Improving App Change details

[100mik]

A set of changes intended to improve the observability that the app-change feature offers while improving how users interact with stored app changes.

This epic currently includes these issues:

• Add app-change describe command to allow the user to view diffs for deployed changes #338
• Improve how the user can sort and filter app-changes while listing them #339
• Add app-change delete command which allows easy decluttering of stored app changes #340
• Enhance kapp rename to handle app-changes #341

We are open to suggestions about how we can add more value to stored app-changes. Feel free to put down your thoughts in this thread!

[rohitagg2020]

Moving it to low priority.