Cherry picking fixes for may merge

[michellethomas]

• fixing LIKE constant name ([Explore][Adhoc Filters] fixing LIKE constant name apache/superset#5110) (cherry picked from commit f3778c3)
• [crud] Improving performance ([SQLA] Improving performance by disabling editing Associated Charts apache/superset#5136) (cherry picked from commit f102eab)
• Fixing time table viz for adhoc metrics (Fixing time table viz for adhoc metrics apache/superset#5117) (cherry picked from commit ff4b103)
• adding null checks to adhoc filter popover ([Explore][Adhoc Filters] adding null checks to adhoc filter popover apache/superset#5111) (cherry picked from commit 40fadfc)

@john-bodley @graceguo-supercat @timifasubaa

[michellethomas]

I'll also cherry-pick John's migration when it's merged apache#5135

[codecov-io]

Codecov Report

Merging #50 into airbnb-master will not change coverage.
The diff coverage is 100%.

@@              Coverage Diff               @@
##           airbnb-master      #50   +/-   ##
==============================================
  Coverage          77.45%   77.45%           
==============================================
  Files                 44       44           
  Lines               8672     8672           
==============================================
  Hits                6717     6717           
  Misses              1955     1955

Impacted Files	Coverage Δ
superset/connectors/sqla/views.py	70.47% <100%> (ø)	⬆️

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