Omit quotations from string parameter suggestions

### 👓 What did you see?

When there is a step with Cucumber expression {string} then after selecting this suggestion:
1. all text including double quotes is selected
2. VS code is suggesting some values for parameter itself (I didn't find out what is mechanism e.g from currently opened file etc)



### ✅ What did you expect to see?
1. only text inside double quotes is selected
2. default value should be just empty string because there is very little chance to have valid suggestion for parameter

Surprisingly it works for regular expression e.g /^PATCH request to "(.*)" with body:$/
Also it's ok with Cucumber expression {int} because there is no need for double quotes.

### 📦 Which tool/library version are you using?
Cucumber plugin: v1.7.0, VS code: 1.74.2

### 🔬 How could we reproduce it?

Steps to reproduce the behavior:

Install Cucumber extension v1.7 onto latest VS Code
Have step definition with Cucumber expression {string}
Create any feature file
Use autocomplete suggestion for this step