refactor(driver): move dbms to index module

[hanxiao]

also remove the hint of post_init may takes too long as it is too verbose and hurting our principle of "exposing less"

[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (master@1825529). Click here to learn what that means.
The diff coverage is 100.00%.

@@            Coverage Diff            @@
##             master    #2312   +/-   ##
=========================================
  Coverage          ?   90.89%           
=========================================
  Files             ?      221           
  Lines             ?    11786           
  Branches          ?        0           
=========================================
  Hits              ?    10713           
  Misses            ?     1073           
  Partials          ?        0           

Flag	Coverage Δ
daemon	50.98% <55.00%> (?)
jina	91.06% <100.00%> (?)

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
jina/drivers/index.py	97.95% <100.00%> (ø)
jina/executors/__init__.py	92.65% <100.00%> (ø)

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 1825529...7dba2be. Read the comment docs.

[github-actions]

Latency summary

Current PR yields:

• 😶 index QPS at 941, delta to last 3 avg.: +0%
• 🐢🐢 query QPS at 13, delta to last 3 avg.: -6%

Breakdown

Version	Index QPS	Query QPS
current	941	13
1.1.5	943	13
1.1.4	946	14

Backed by latency-tracking. Further commits will update this comment.