[Types] R2Objects stricter type

[DaniFoldi]

Hi 👋

When listing objects in R2, a value of type R2Objects is returned.

Similarly, in KV KVNamespaceListResult is returned, which a union type where the cursor and list_complete keys are strictly combined to provide either the result of a complete list or an incomplete list - which are the only possible outcomes.

Currently, R2Objects has this type:

declare interface R2Objects {
  objects: R2Object[];
  truncated: boolean;
  cursor?: string;
  delimitedPrefixes: string[];
}

Which I believe could be changed to

declare type R2Objects = {
  objects: R2Object[];
  delimitedPrefixes: string[];
} & (
  | {truncated: true; cursor: string}
  | {truncated: false}
)