Filter post unwind

[findingrish]

Effect of applying filter pre and post unwind is different, since unwind creates multiple document for the source document.
Applying the same filters again.

[codecov]

Codecov Report

Merging #79 (66a48f9) into main (a6c55e1) will increase coverage by 0.12%.
The diff coverage is 95.45%.

@@             Coverage Diff              @@
##               main      #79      +/-   ##
============================================
+ Coverage     77.78%   77.91%   +0.12%     
- Complexity      361      364       +3     
============================================
  Files            65       65              
  Lines          1796     1811      +15     
  Branches        178      179       +1     
============================================
+ Hits           1397     1411      +14     
  Misses          284      284              
- Partials        115      116       +1     

Flag	Coverage Δ
integration	77.91% <95.45%> (+0.12%)	⬆️
unit	48.37% <59.09%> (-0.07%)	⬇️

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Impacted Files	Coverage Δ
...ocumentstore/expression/impl/UnnestExpression.java	72.72% <80.00%> (+1.29%)	⬆️
.../mongo/parser/MongoFilterTypeExpressionParser.java	100.00% <100.00%> (ø)
...re/mongo/parser/MongoFromTypeExpressionParser.java	100.00% <100.00%> (ø)

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[suresh-prakash]

This may clearly affect performance.
Can't filter be just done after unwind?

[findingrish]

The filter step before unwind is necessary to reduce the amount of documents unwind is applied to.
Post filter is not affecting performance but yeah the forced filtering can reduce flexibility of this interface.
As discussed will introduce a filter inside the UnnestExpression for flexible filtering post each unwind step.

[github-actions]

Unit Test Results

  14 files  ±0    14 suites  ±0   5s ⏱️ -1s
  93 tests +2    93 ✔️ +2  0 💤 ±0  0 ❌ ±0 
143 runs  +2  143 ✔️ +2  0 💤 ±0  0 ❌ ±0 

Results for commit ef9124f. ± Comparison against base commit a6c55e1.