Add columnChart display type to GLQL

Summary

• Adds a columnChart GLQL display type, supporting multiple metrics and dimensions ( see screenshots below for detailed breakdown)
• Supports displayConfig.stacked to stack multiple metrics (only respected in single-dimension - for multiple dimensions it's stacked by default)

Stacked on top of !228129 (closed) (analytics mode infrastructure).

Related to GLQL: Add columnChart display type support (glql#133 - closed)

Example queries

• 1 dimension / 1 metric:

mode: analytics
query: type = CodeSuggestion
dimensions: language
metrics: totalCount
display: columnChart

• 1 dimension / 2 metric (grouped by default):

mode: analytics
query: type = CodeSuggestion
dimensions: language
metrics: totalCount, acceptanceRate
display: columnChart

• 1 dimension / multiple metrics (grouped by default):

mode: analytics
query: type = CodeSuggestion
dimensions: language
metrics:  shownCount, acceptedCount, rejectedCount
display: columnChart

• 1 dimension / 2 metrics (stacked):

mode: analytics
query: type = CodeSuggestion
dimensions: language
metrics: shownCount, acceptedCount
display: columnChart
displayConfig:
 stacked: true

• 1 dimension / multiple metrics (stacked):

mode: analytics
query: type = CodeSuggestion
dimensions: language
metrics: shownCount, acceptedCount, rejectedCount
display: columnChart
displayConfig:
 stacked: true

• 2 dimensions / 1 metric (stacked by default)

mode: analytics
query: type = CodeSuggestion
dimensions: user, language
metrics: totalCount
display: columnChart

• 2 dimensions / 2+ metrics (not supported)

mode: analytics
query: type = CodeSuggestion
dimensions: user, language
metrics: totalCount, acceptanceRate
display: columnChart

2+ dimensions (not supported)

mode: analytics
query: type = CodeSuggestion
dimensions: user, language, timestamp
metrics: totalCount
display: columnChart