Suggested variable name completions have trouble with leading $, @, and #

[jkyeung]

Describe the bug
When a variable's name begins with @ or #, it seems to never show up in the suggested completions. When a variable's name starts with $, it can show up in the suggestions, but accepting it doubles up the $.

To Reproduce
Steps to reproduce the behavior:

1. Declare a variable $myvar (in RPG).
2. Begin an assignment statement with $m.
3. Accept the suggested $myvar.
4. Notice that your cursor now follows $$myvar.

Expected behavior
Accepting $myvar results in $myvar, not $$myvar.

Screenshots
I will add upon request.

Environment (please complete the following information):

• Extension version: 2.3.1
• IBM i OS version: 7.4

Additional context
The behavior for leading @ and # is very different. If that needs to be a separate issue, I can create one.

[worksofliam]

Closing as tracking with #285