Add push upgrade for event offline receipt

Add push upgrade for event offline receipt

This follows our historical practice of doing push receipts by
- adding the relevant receipt to the array of template in the upgrade
notification and
- (optionally) noting deprecated params on CRM_Utils_Token::getDeprecatedTokens

I didn't add lineItem to the deprecated array as it is pretty legit
to assign that within a foreach loop.

I also removed the assigns for the variables which are no longer relevant -
this can be followed up with more tidy up (some of which resolves php8.x issues)

Note that the template still uses
$billingName & $address - resolved in
https://github.com/civicrm/civicrm-core/pull/27692
$customGroup - resolved in https://github.com/civicrm/civicrm-core/pull/27596
(actually the variable remains but becomes non-leaky)
$credit_card_date,$credit_card_type (I propose moving to a paymet token)
$credit_card_expiry (I propose removing)
$event.confirm_text - addressed in https://github.com/civicrm/civicrm-core/pull/27162