[FEATURE] Support continues offset for kop

[aloyszhang]

Is your feature request related to a problem? Please describe.
As described in #175, the design of map between kakfa offset and pulsar <LedgerId, EntryId> has potential risk of using up ledgerId which leads to cluster can't work.

And also cause problem in #218

Describe the solution you'd like
Now, pulsar has support continuous index at message level, we can use this feature to refacotr the implement of offset management in KOP.

Additional context
After upgrade the latest dependency of pulsar, see #289, I will work on this feature.
And this feature will resolve #175 and #218 once for all.