BKClient tests with BookieErrors

[reddycharan]

FEATURE REQUEST

1. Please describe the feature you are requesting.

This is testcode request. end-to-end tests for validating BKClient readEntry calls incase of combination of bookie timeouts and data corruption.

2. Indicate the importance of this issue to you (blocker, must-have, should-have, nice-to-have). Are you currently using any workarounds to address this issue?

this is just new testcode. Must have for us, since these tests are missing in the current codebase.