Use code editor autocomplete provider from grafana/experimental

[sunker]

Discussed in https://github.com/grafana/timestream-datasource/discussions/125

^{Originally posted by sunker January 11, 2022}
The BI squad has recently added an autocomplete provider to the grafana/experimental package. See https://github.com/grafana/grafana-experimental/tree/main/src/sql-editor. The autocompletion provider is based on the provider that we built for CloudWatch golden eye, but it has been modified in a way so that it allows the consumer to specify a custom language. The new provider is already used in the big query data source, but the redshift data source will likely be the first consumer that uses a custom language.

[vickyyyyyyy]

This should be worked on after the Redshift ticket is done: grafana/redshift-datasource#108