Problem: Vim9: No support for type aliases
Solution: Implement :type command
A type definition is giving a name to a type specification. This also known
type alias.
:type ListOfStrings = list<string>
The type alias can be used wherever a built-in type can be used. The type
alias name must start with an upper case character.
closes: #13407
Signed-off-by: Christian Brabandt <cb@256bit.org>
Signed-off-by: Yegappan Lakshmanan <yegappan@yahoo.com>