[Feature] Move duplicate prop check to a test instead of runtime

# **Feature Request**

From Josh Goldberg (thanks)

> There is logic right now to assert that no two plugins declare the same prop:

```tsx
const propsCheck: string[] = [];

transformationPlugins.forEach(({ props = [] }) => {
props.forEach((prop) => {
if (propsCheck.includes(prop)) {
throw new Error(`Option ${prop} already exists!`);
}
propsCheck.push(prop);
});
});
```

> This seems reasonable. I’d suggest doing this at test time so that runtime users don’t need to run that code.

> I’d also personally lean towards a `Set` for an ever so slightly faster check (not urgent at all):

```tsx
const propsCheck = new Set()

transformationPlugins.forEach(({ props = [] }) => {
props.forEach(prop => {
if ( propsCheck.has(prop) ) {
throw new Error(`Option ${prop} already exists!`);
}
propsCheck.add(prop);
});
});
```

## Solution

Create a new test that checks all of the plugins for duplicate props. It can use the logic above to perform the check.

Then remove this check from the `constructCloudinaryUrl` function