[18.0][ADD] website_select2

[hbrunn]

This module applies select2 to select elements on the website or portal, allowing users to incrementally search within the available options:

To use this module, you need to:

1. Go to /my/account
2. Observe that ie. the country dropdown is searchable

Advanced usage:

• To disable select2 on some specific select element, set class select2-disable
• To force select2 on a select elements with few options, set class select2-force
• To pass custom options to select2 for some specific select element, set attribute data-select2-options="{...}"