Auto-complete inserts extra quote for strings

[dklilley]

Describe the bug
When auto-completing a string in a function call, the auto-complete inserts an extra quote at the end, resulting in a syntax error.

To Reproduce
Steps to reproduce the behavior:

1. In a MATLAB file, type plot(x, y, "Col - with VS Code's paren- and quote-completions, this will result in the following being on the line: plot(x, y, "Col")
2. There should be a tab completion for "Color" showing - select it
3. This will result in an extra quote being inserted: plot(x, y, "Color"")