[typescript-fetch]: Revert "[typescript-fetch] Support deepObject query params (#6075)"

[haraldF]

This reverts commit 354f195.

It became superfluous due to some other changes in runtime and changing
of the queryParameters in d9a6f4d

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[haraldF]

@TiFu @taxpon @sebastianhaas @kenisteward @Vrolijkx @macjohnny @topce @akehir @petejohansonxo @amakhrov

review please? You can find the full discussion at #6706