Fix Collision In Generated Paging Operations

[jorgerangel-msft]

Consider this tsp:

interface Foo {
  @route("/list")
@doc("List things with nextlink")
@convenientAPI(true)
@list
op List(): {
  @pageItems
  things: Thing[];

  @nextLink next?: url;
};

@route("/listAll")
@doc("List things with nextlink")
@convenientAPI(true)
@list
op ListAll(): {
  @pageItems
  things: Thing[];

  @nextLink next?: url;
};
}

The generator does internal renaming of operations named "List" to "GetAll". In doing so, this causes a collision in the generated code for this sample since both operations would end up having the same name.