KT-4750 [Pt.1] String Interpolation -> String Template

This intention converts a String that is formed using concatenation to one that is formed using a template. 

Example:
```kotlin
"a = " + a + ", b = " + (compute1() + 222) + " :)"
```
becomes:
```kotlin
"a = $a, b = ${compute1() + 222} :)"
```