Updating the codebase to php 8

[mamazu]

Problem description

We want to use all the new and good stuff from PHP8. But not make any BC breaking changes.

• Using match
• Constructor Property Promotion
• New string function (str_starts_with, str_ends_with, str_contains)
• Using the new fn callback syntax

Proposed solution

To reduce amount of errors most of the refactoring should be done with rector.