Revert "Seperated BlockStatus class from chain.h file and updated .h and .cpp dependencies."

Summary: This reverts commit 62591dfadea320241e8c02162c2d9d4fd935dcbd.

Test Plan:

make

Reviewers: #bitcoin_abc, schancel

Reviewed By: #bitcoin_abc, schancel

Subscribers: teamcity

Differential Revision: https://reviews.bitcoinabc.org/D1707