Root page separates abandoned

[Scooletz]

This PR changes the structure of the root pages in Paprika database.

Previously, each root occupied just one page (4kb). The number of root pages was defined by the historyDepth so that the first pages in the database were: [root0, root1, ..., rootN, regular0, regular1, ...] where N = historyDepth.

This PR changes this structure expanding each root page and allowing to make it of size 2*PageSize (8kb) or even bigger in the future. The changes needed for atomicity are still preserved in the first page, while the second is used as an extension. This makes the first pages in db look like the following: [root0a, root0b, root1a, root1b, ..., rootNa, rootNb].

This extension allows to change the root structure to the following:

1. 0th page:
   1. metadata - metadata of the root
   2. state - the address of the state root page
   3. ids - a fanout list
   4. storage - a fanout list
   5. storage merkle - a fanout list
2. 1th page:
   1. abandoned page list - full 4 kb

where a fanout list is a list of 256 addresses (1kb in total) that consumes 2 nibbles from the path.

[github-actions]

Package	Line Rate	Branch Rate	Health
Paprika	85%	80%	✔
Summary	85% (4193 / 4920)	80% (1346 / 1680)	✔

Minimum allowed line rate is 75%