Error rates: Better error messages for image deletion failure

[bwateratmsft]

One of the most common two errors we see from telemetry relate to failed image deletion, for the following two reasons:

• image has dependent child images
• image is being used by running container xxx

We should catch these two, provide a clearer error message, and suppress the Report Issue button.

See #1391, #1354, #1362, #1357, #1208, #1126, and probably even more.

[bwateratmsft]

Similar idea of reducing error rate w/ #1323, #1383.

[v-dantch]

Verified on the candidate 20200122.2, display below notification when deleting an image which cannot be deleted.