Doc: replace preserved cycles by the adequat new constant

Preserved cycles has been split into 3 new constants, the documentation should reflect that, everywhere.

• !11220 (comment 1725501835) (handled in !13869 (merged))

The newly introduced constant (blocks_preservation_cycles) should also be listed somewhere. And it it's no more in the PoS constants, some references must be redirected.

In particular, section https://tezos.gitlab.io/user/history_modes.html#history-mode-additional-cycles refers to these PoS constants here for retrieving "the preserved_cycles protocol parameter"; in this case, both the name of the constant and the target ref should be fixed.

• !11220 (comment 1725501846):

is it useful to create a new constants section in the AI/staking page for adaptive_issuance_activation_delay and delegate_parameters_activation_delay?

(although adaptive_issuance_activation_delay is not a parametric constant)