Naming collision in generated files

**Describe the bug**
I had an enum called `DataQuery` in my schema. I also defined a query operation `DataQuery`. I'm using the `react-query` plugin, it outputs a function `useDataQuery` and a corresponding `DataQuery` interface for the return type. It also generates a `DataQuery` corresponding to my enum. This generates a collision `Enum declarations can only merge with namespace or other enum declarations.ts(2567)`

**Expected behavior**
I suppose it should refuse to generate the code rather than generating invalid code. It was easy enough to workaround by renaming my query or enum, but the tool could be a bit more defensive.