Use concurrency control in Redis store's Multi()

[tcnghia]

Description

Change Multi() to use same setQuery and delQuery mechanisms as Set() and Delete().

Issue reference

Please reference the issue this PR will close: #375

Checklist

Please make sure you've completed the relevant tasks for this PR, out of the following list:

• Code compiles correctly
• Created/updated tests
• Extended the documentation / Created issue in the https://github.com/dapr/docs/ repo: dapr/docs#[issue number]

[youngbupark]

LGTM. thanks for the cleaning up the code as well.
Please do backward compat test similar to the below scenario manually.

with 0.10.0 dapr

1. dapr uninstall --all
2. dapr init
3. dapr run
4. call transaction api to save teststate state with oldvalue value

with your change

1. build new daprd with your change
2. copy new daprd build to ~/.dapr/bin/
3. dapr run
4. call get state api to get teststate state
5. ensure that returned state value is oldvalue
6. call transaction api to save teststate state with newvalue value
7. call get state api to get teststate state
8. ensure the returned state value is newvalue

[youngbupark]

please run the backward compat test before merging.

[tcnghia]

@youngbupark thanks for the instruction. I've confirmed backward compat using that sequence.

[codecov]

Codecov Report

Merging #466 into master will increase coverage by 0.27%.
The diff coverage is 75.00%.

@@            Coverage Diff             @@
##           master     #466      +/-   ##
==========================================
+ Coverage   28.27%   28.54%   +0.27%     
==========================================
  Files          79       79              
  Lines        6263     6263              
==========================================
+ Hits         1771     1788      +17     
+ Misses       4296     4273      -23     
- Partials      196      202       +6     

Impacted Files	Coverage Δ
state/redis/redis.go	25.14% <75.00%> (+9.14%)	⬆️
state/cloudstate/cloudstate_crdt.go	9.05% <0.00%> (+0.43%)	⬆️

---

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 e5a50cb...16d6224. Read the comment docs.