Remove btn-secondary class on datatables button
btn-outline-secondary shouldn't be added with btn-secondary anymore with
4.4.1

JIRA INFRA-2021 #action In Progress

JIRA INFRA-1790 #action In Progress

- Restrict the width of the vars column
- Make the children and hosts a list of comma separated words with space
  to allow line break

JIRA INFRA-763

selectize-bootstrap4-theme v2.0.2 from
https://github.com/const-se/selectize-bootstrap4-theme

To use selectize on a Select or MultiSelect field, add the
selectize-default class. It initializes selectize with the default
options.

JIRA INFRA-644 #action In Progress

This is not directly supported by CodeMirror.
See https://github.com/codemirror/CodeMirror/issues/850

Add cm-resize library from https://github.com/Sphinxxxx/cm-resize

JIRA INFRA-543 #action In Progress

JIRA INFRA-412