Function stringIncludesOnlyOnce

stringIncludesOnlyOnce(search: string): ((value: unknown) => value is string)
Checks if given search value appears just onces in given value.

Example
```
const includesCommaOnce = stringIncludesOnlyOnce(",");
includesCommaOnce("value,value"); // true
includesCommaOnce("value,value,value"); // false
includesCommaOnce("value"); // false
```
Returns
Curried function with search in context.
Parameters
- search: string
  
  Value to search.
Returns ((value: unknown) => value is string)
- - (value: unknown): value is string
  - Parameters
    - value: unknown
    Returns value is string
- Defined in src/validations/stringIncludesOnlyOnce.ts:18