Rename defaultPageParam to initialPageParam

[Moshyfawn]

How do you feel about renaming the new Infinite Queries defaultPageParam argument to initialPageParam?

The use of the word "default" implies the value can be used as a fallback when in case of page parameters, it "stands" in line with the rest of the page parameters: it can be used by explicitly "selecting" it via the Infinite Queries methods like fetchNextPage or fetchPreviousPage; it's not being used in the context of "reset to default page" type of method.

Furthermore, "initialPageParam" name is inline with the Query API argument initialData (and initialDataUpdatedAt) and the way it's been logically handled by queries.

Let me know what you think. I can already provide a PR since I had to dig through the source code to justify my proposal anyway 😊

[TkDodo]

I like it. Please make a PR to beta ❤️

[Moshyfawn]

#5888