Add JoinedFormatter for dynamic variables in where sentence

[liuzx32]

Description
The users can use ${START_DATE} and ${END_DATE} in where filter which in the WebUI.
And the dynamic variables ${START_DATE} and ${END_DATE} are from the building date of Cube.

Refer-issue: https://issues.apache.org/jira/browse/KYLIN-4156

[asf-ci]

Can one of the admins verify this patch?

[codecov-io]

Codecov Report

Merging #813 into master will increase coverage by 0.02%.
The diff coverage is 57.89%.

@@             Coverage Diff              @@
##             master     #813      +/-   ##
============================================
+ Coverage     25.61%   25.63%   +0.02%     
- Complexity     6048     6060      +12     
============================================
  Files          1398     1399       +1     
  Lines         83511    83566      +55     
  Branches      11699    11705       +6     
============================================
+ Hits          21391    21423      +32     
- Misses        60065    60087      +22     
- Partials       2055     2056       +1

Impacted Files	Coverage Δ	Complexity Δ
...ain/java/org/apache/kylin/job/JoinedFlatTable.java	0% <0%> (ø)	0 <0> (ø)	⬇️
...ain/java/org/apache/kylin/job/JoinedFormatter.java	61.11% <61.11%> (ø)	11 <11> (?)
...he/kylin/job/impl/threadpool/DefaultScheduler.java	74.41% <0%> (-2.33%)	12% <0%> (ø)
.../apache/kylin/cube/cuboid/TreeCuboidScheduler.java	63.84% <0%> (-2.31%)	0% <0%> (ø)
...rg/apache/kylin/cube/inmemcubing/MemDiskStore.java	70.21% <0%> (+0.6%)	7% <0%> (ø)	⬇️
...org/apache/kylin/rest/util/QueryRequestLimits.java	40.47% <0%> (+4.76%)	6% <0%> (+1%)	⬆️

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[coveralls]

Pull Request Test Coverage Report for Build 4953

• 35 of 57 (61.4%) changed or added relevant lines in 2 files are covered.
• 5 unchanged lines in 3 files lost coverage.
• Overall coverage increased (+0.02%) to 28.1%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
core-job/src/main/java/org/apache/kylin/job/JoinedFlatTable.java	0	3	0.0%
core-job/src/main/java/org/apache/kylin/job/JoinedFormatter.java	35	54	64.81%

Files with Coverage Reduction	New Missed Lines	%
core-job/src/main/java/org/apache/kylin/job/JoinedFlatTable.java	1	0.0%
core-cube/src/main/java/org/apache/kylin/cube/cuboid/TreeCuboidScheduler.java	2	68.46%
core-job/src/main/java/org/apache/kylin/job/impl/threadpool/DefaultScheduler.java	2	80.23%

Totals
Change from base Build 4952:	0.02%
Covered Lines:	23482
Relevant Lines:	83566

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💛 - Coveralls

[nichunen]

LGTM