SQL autocompletion support

[sunker]

We should add support for syntax highlighting and autcomplete in the Redshift data source. The work

Tasks

• Autocomplete: Render SQL editor in case feature toggle is enabled  #150
• Define and load custom redshift sql language #153
• Make sure Monaco redshift language is up to date with language ref #155
• Add default completion item provider to experimental package in the case standard sql is used SQL Autocomplete: Add standard completion item provider  grafana-experimental#42
• Support schema in table identifiers SQL Autocomplete: Support schema in table identifiers grafana-experimental#43
• Create custom completion item provider which resolves redshift table names and redshift column names #168
• Add support for context aware autocompletion for macros #170
• Provide autocompletion for schemas #172
• Always render new code editor and remove feature flag from Grafana

There are a few things that I don't like about the SQL Editor api in grafana/experimental. For example, functions, operators and supported macros are currently being specified in the autocompletion provider and not in the language. This causes a discrepancy between the syntax highlighting support and the autocompletion support. I'll raise an issue about this in the experimental package so that it can be discusses with the BI squad.

[sunker]

Temporary putting this issue on hold so that I can focus on Grafana 9 critical issues instead

[sarahzinger]

@sunker is it cool if I move this to backlog?

[sunker]

Yes sure!

[vickyyyyyyy]

The Timestream and Athena tickets should be picked up once this is done