addrman: detect on-disk corrupted nNew and nTried during unserialization

Summary:

Negative `nNew` or `nTried` are not possible during normal operation.
So, if we read such values during unserialize, report addrman corruption.

Backport of core#22455.

Test Plan:

ninja all check-all

Reviewers: #bitcoin_abc, PiRK

Reviewed By: #bitcoin_abc, PiRK

Differential Revision: https://reviews.bitcoinabc.org/D12276