ModelList - sorting and then resizing causes loadItems() to be called while dragging/resizing

[tma-isbx]

https://github.com/ISBX/isbx-loopback-cms/blob/master/client/app/dashboard/model/list/ModelList.js#L692

The $watch on the 'sortInfo' is constantly fired, and newVal !== oldVal because newVal and oldVal also include the column, which includes the columns width.

Proposed solution: instead of comparing all of newVal and oldVal, we should compare if the sort attributes we depend on have changed (sortInfo.fields and sortInfo.directions).

https://github.com/ISBX/isbx-loopback-cms/blob/master/client/app/dashboard/model/list/ModelList.js#L295