Voiceover accessibility improvement

[k00ka]

This pull request includes a

• [x ] Bug fix
• New feature
• Translation

The following changes were made

• Apple iOS's VoiceOver accessibility solution default settings require users to click twice to activate a widget. On the first click, select2's dropdown is opened. On the second click it is closed. This means VoiceOver users cannot complete a select2 field.
• The solution is ignore the second and subsequent clicks on the field. Rather than toggle, any clicks on the field will either open the dropdown, or be ignored.
• Single- and multiple-select fields are implemented separately, and so there are two patches, plus myriad other changes caused by rebuilding and minifying the resulting package.

If this is related to an existing ticket, include a link to it as well.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.