Reapply "net: skb: introduce and use a single page frag cache"

Reapply "net: skb: introduce and use a single page frag cache"

This reverts commit 011b0335903832facca86cd8ed05d7d8d94c9c76.

Sabrina reports that the revert may trigger warnings due to intervening
changes, especially the ability to rise MAX_SKB_FRAGS. Let's drop it
and revisit once that part is also ironed out.

Fixes: 011b03359038 ("Revert "net: skb: introduce and use a single page frag cache"")
Reported-by: Sabrina Dubroca <sd@queasysnail.net>
Link: https://lore.kernel.org/6bf54579233038bc0e76056c5ea459872ce362ab.1739375933.git.pabeni@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>