A code fix to change colon to equals in record bindings

Change this:
```fsharp
type Band = { Name : string }

let band = { Name : "New Order" }
```

to this:
```fsharp
type Band = { Name : string }

let band = { Name = "New Order" }
```

_Originally posted by @0101 in https://github.com/dotnet/fsharp/issues/15456#issuecomment-1600547808_