Standardize sort icons for data table and message list.

[linuspahl]

Description

The icons we use for ascending and descending sort are unified and the sorting works as expected, but currently the icons are not standardized, compared with other applications.

Currently we display the following icons.

Ascending sort (A...Z):

Descending sort (Z...A):

Instead we should consider displaying the following icons.

Ascending sort (A...Z):

Descending sort (Z...A):

We can also create a shared component like SortIcon which we can be reused everywhere where we want to display a sort icon. Ideally it would also support multi sort.

• Graylog Version: 5.0