Function shortenString

shortenString(value, startCount?, endCount?, ellipse?): string
Shortens a string by removing characters from the middle and replacing them with an ellipse.
Parameters
- value: string
  The string to shorten
- Optional startCount: number
  The number of characters to keep at the start of the string
- Optional endCount: number
  The number of characters to keep at the end of the string
- Optional ellipse: string
  The string to use as the ellipse (default: '...')
Returns string
The shortened string
Example
```
shortenString('0x7a7a7229292286592739473748234343434532345', 4, 4) // '0x7a...2345'
shortenString('0x7a7a7229292286592739473748234343434532345', 4, 4, '***') // '0x7a***2345'
shortenString('0x7a7a7229292286592739473748234343434532345', 6, 4, '...') // '0x7a7a...2345'
```