Date parsing improvements

[hughess]

Summary

This PR implements improved date parsing.

Original Problems

• Each database returns slightly different date strings
• Each browser interprets and parses dates differently depending on the format of the string
• Safari and Firefox return Invalid Date in several scenarios
• Chart not able to use dates from Snowflake if they include a timestamp

Solution

• Splits getParsedDate into a few functions and saves them in a module called dateParsing
  • standardizeDateString - Parses any date string and attempts to get it into a standard format YYYY-MM-DDTHH:MM:SS
  • standardizeDateColumn - Applies standardizeDateString to a full column in a data object
  • convertColumnToDate - Applies standardizeDateString to a full column plus new Date()
• Adds date string standardization to Chart.svelte
  • ECharts is not able to read timestamps returned from Snowflake if they contain a timezone - standardizing the string fixes this
  • Due to an issue in the tidyJS library, we're not able to use Date objects in multi-series charts, so using standardized strings is the preferred solution until that issue is resolved
• Closes Snowflake TIMESTAMP_TZ type not working as expected #388

Remaining Issues

This is likely not a good long-term solution - it relies on date strings being in a close enough format to be able to convert them to the standardized YYYY-MM-DDTHH:MM:SS format.

Potential future improvements:

• Centralize the date parsing logic alongside the type inference performed by Evidence in dbcommons
  • This would run the logic once rather than having to run it from within each component where data is used
• Return Date objects from each database connector rather than strings
  • This would eliminate the string parsing issues for most database connectors
  • Potential issue here would be how each connector converts to the Date object - there may be timezone conversion issues there as well, and it may be challenging to get all db connectors treating all dates in the same way
• We will need to build solid support for timezones eventually - this implementation effectively ignores timezones in order to standardize all outputs, but this is a naive approach and while it should cover the majority of use cases, we should only use it in the short-term

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Name	Status	Preview	Updated
evidence-docs	✅ Ready (Inspect)	Visit Preview	Oct 5, 2022 at 4:06PM (UTC)

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🦋 Changeset detected

Latest commit: fe65489

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 3 packages

Name	Type
@evidence-dev/components	Patch
@evidence-dev/evidence	Patch
evidence-test-environment	Patch

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