All but first returns empty list but not empty YailList

[ewpatton]

Describe the bug

When the all but first block is used on a list of length 1 returns an empty Scheme list. This causes checks like is a list? to return false because they expect items conforming to YailList.

Affects

• Designer
• Blocks editor
• Companion
• Compiled apps
• Buildserver
• Debugging
• Other... (please describe)

Expected behavior

all but first should return an empty YailList rather than an empty list when its input is a length of 1 list.

Steps to reproduce

See this post on the nb191 testing announcement: https://community.appinventor.mit.edu/t/help-test-nb191/76301/24?u=ewpatton

[ewpatton]

Fixed by #2823