allow mvn build with development webpack; fix instances default value

[jadami10]

This is ui and bugfix

• fixes a bug from #8970 Minion tab in Pinot UI #8978 where instances should default to an array
  • this causes the UI to perpetually have a spinner but wasn't actively breaking
• updates the pom.xml npm build option for the controller
  • the default is still build
  • adds a new build-dev to package json where you can build in development mode
  • this lets you do a min command that packages without minifying for an environment like QA so you can actually see the code
• fixes a few typos

This was tested by building pinot-controller in IntelliJ with the new npm.script option set to build-dev. The ui ran with non-minified code in main.js. Then I ran realtime Quickstart to ensure the /instances worked correctly.

[codecov-commenter]

Codecov Report

Merging #9179 (19e4a05) into master (7bd4dd4) will increase coverage by 0.02%.
The diff coverage is 68.78%.

@@             Coverage Diff              @@
##             master    #9179      +/-   ##
============================================
+ Coverage     69.90%   69.93%   +0.02%     
+ Complexity     5003     4758     -245     
============================================
  Files          1847     1847              
  Lines         98562    98684     +122     
  Branches      14970    15007      +37     
============================================
+ Hits          68900    69014     +114     
+ Misses        24821    24818       -3     
- Partials       4841     4852      +11     

Flag	Coverage Δ
integration1	26.13% <18.47%> (-0.15%)	⬇️
integration2	24.83% <17.83%> (-0.02%)	⬇️
unittests1	67.04% <68.15%> (+0.06%)	⬆️
unittests2	15.31% <0.00%> (-0.02%)	⬇️

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

Impacted Files	Coverage Δ
...operator/filter/RangeIndexBasedFilterOperator.java	70.93% <ø> (ø)
.../pinot/core/query/reduce/filter/NotRowMatcher.java	0.00% <0.00%> (ø)
...core/operator/filter/predicate/PredicateUtils.java	68.18% <38.46%> (-5.90%)	⬇️
...e/operator/dociditerators/SVScanDocIdIterator.java	75.25% <65.45%> (-18.63%)	⬇️
...ot/core/query/reduce/filter/RowMatcherFactory.java	44.44% <75.00%> (ø)
.../pinot/core/operator/docidsets/SVScanDocIdSet.java	100.00% <100.00%> (ø)
...inot/core/operator/filter/FilterOperatorUtils.java	87.50% <100.00%> (+0.15%)	⬆️
.../core/operator/filter/ScanBasedFilterOperator.java	100.00% <100.00%> (ø)
...ava/org/apache/pinot/core/plan/FilterPlanNode.java	82.44% <100.00%> (+0.27%)	⬆️
.../pinot/core/query/reduce/GapfillFilterHandler.java	85.71% <100.00%> (ø)
... and 51 more

📣 Codecov can now indicate which changes are the most critical in Pull Requests. Learn more