fix: add more recent zero point for wallet birthday (see issue #4176)

[jorgeantonio21]

Description
--- Add logic to tackle issue #4176, which aims at improving birthday representation for Cipher Seed generation.

Motivation and Context
--- The goal of this PR is to resolve issue #4176. The current version is supposed to allow a more recent genesis for wallet birthdays (it actually depends on the genesis block of the Tari network, we wish to work with). Moreover, it updates the version. Moreover, if the birthday does not fit within the u16 type range, we update to a new version.

How Has This Been Tested?
--- Add simple tests to check if logic is correct.

[jorgeantonio21]

We introduce a Birthday type which encapsulates the logic to deal with a zero point in time, and updates this zero point in time
every 2^16 days. This is needed in order to have a well defined birthday for perpetuity.

The current implementation relies on the genesis block of a chosen network. At the moment, we default to the Dibbler test-net, however this should be updated when the main-net is released.

One can argue that this functionality is not at all required, and we should instead hardcode an initial zero point in time, and update it to the mainnet, at launch time.