Implement storage data retention for accounts

[MichalTuleja]

Description

Make sure that blockchain data are not kept forever. Perform a regular cleanup of the data used in the storage.

Space reclaim process has to be performed on the following databases:

• Accounts

Motivation

• Proper data retention allows to control the amount of disk space used for storing blockchain data

Acceptance Criteria

• Older data is deleted
• Disk space is reclaimed

[MichalTuleja]

This issue does not need to be solved as Lisk Service does not store accounts by default. The new concept changes the approach for storing data; there is no need to implement it.