Add wxt_ext_carousel module to enable WET carousel block type

[smulvih2]

Add wxt_ext_carousel sub-module to enable a custom block type for WET carousel display.

[sylus]

I don't think the distro has field_permissions?

Also we do support carousel already unless this is different?

See this migrated content page using slideshow

[smulvih2]

@sylus I removed the dependency on field_permissions module and tested with fresh install of WxT 4.3.x to ensure it installs correctly.

This approach would add the following capabilities beyond what is currently available:

• Link and link text with each carousel item
• Translation of image and link fields
• Image style
• Transition type selection (fade, slide, vertical slide)
• Could easily add other config options like s1 vs s2, transition speed