Add an overload to StringPool.GetOrAdd method which accepts an interpolated string

### Overview

It would be really nice if there is an overload for the StringPool.GetOrAdd method which accepts a custom InterpolatedStringHandler. This InterpolatedStringHandler would create a ReadOnlySpanand use this to get the string from the pool without any string allocation (if available in the pool).

### API breakdown

```csharp
namespace CommunityToolkit.HighPerformance.Buffers;

class StringPool {

public string GetOrAdd(CustomInterpolatedStringHandler value);
}
```

### Usage example

```csharp
using CommunityToolkit.HighPerformance.Buffers;

for (int i = 0; i < 100; i++) {
var array = Foo();
// some code using the array;
}

static Employee[] Foo() {
var result = new Employee[100];
for (int i = 0; i < result.Length; i++) {
string name = StringPool.Shared.GetOrAdd($"Jim {i}"); // this would use the new overload

result[i] = new Employee(name, i);
}
return result;
}

record class Employee(string Name, decimal Salary);
```

### Breaking change?

No

### Alternatives

-

### Additional context

_No response_

### Help us help you

Yes, but only if others can assist