Improve design consistency for modals:
Send to trash, Multi-file upload, Conflict modal, Notifications modal.

[1] Modal with header:

background-color: $ez-color-base-pale;
font-size: 1.5rem;
font-weight: 700;

[2] Modal background color:

background-color: $ez-ground-base-medium;

[3] Order of buttons:
Cancel button should always be placed on the left side.