feat(viz): add funnel chart

[villebro]

SUMMARY

Adds a funnel chart introduced in apache-superset/superset-ui#1006

BEFORE/AFTER SCREENSHOTS OR ANIMATED GIF

TEST PLAN

ADDITIONAL INFORMATION

• Has associated issue:
• Changes UI
• Includes DB Migration (follow approval process in SIP-59)
  • Migration is atomic, supports rollback & is backwards-compatible
  • Confirm DB migration upgrade and downgrade tested
  • Runtime estimates and downtime expectations provided
• Introduces new feature or API
• Removes existing feature or API

[codecov]

Codecov Report

Merging #14480 (46b2b97) into master (90a72bf) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master   #14480   +/-   ##
=======================================
  Coverage   77.11%   77.11%           
=======================================
  Files         952      952           
  Lines       48159    48159           
  Branches     6050     6050           
=======================================
  Hits        37137    37137           
  Misses      10821    10821           
  Partials      201      201           

Flag	Coverage Δ
javascript	71.91% <ø> (ø)

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

Impacted Files	Coverage Δ
...-frontend/src/visualizations/presets/MainPreset.js	0.00% <ø> (ø)

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[zhaoyongjie]

LGTM