Fix column sort arrow icon and sort sequence numbers overlapping

On search result pages with long column headers and multiple sorts selected, the arrow sort icon is inconsistently positioned relative to the order number and sometimes overlapping. This problem appears to be in Nuxeo element nuxeo-data-table-column-sort caused by using relative positioning for the sort icon button and absolute positioning for the order element. (Please refer to attached screenshots)

This issue is also reproducible in nightly-2021 using the following steps:

Steps to Reproduce:

1. Navigate to default search and run with a sample input (e.g. "test")
2. Using table view, enable all columns
3. Apply sorts on each valid column

Expected behavior: all column headers have visible separation between the sort arrow and sequence number

Actual behavior: one or more column headers have the sort arrow and sequence number overlapping (see "Last Contributor" column in screenshot)