Fix wrong jumps when searching for enum types
Add function s:SearchTypeDefinition to search for type definitions only.
Search only single-token identifiers in current function
Allow jumping back with Ctrl-o after jump within function
No ':edit' to jump within current file
Match full string for digits only
Identifiers must not contain non-english letters
Fix (unlikely) jump to wrong position
Jump to function argument
Handle tuple assignments: let (xxx, symbol) =
Jump to enum values instead of type definitions
shellescape directory names
Ignore grep/rg errors
Because not all directories in the directory list exist.
Always reset iskeyword before returning