include a list of available timezones for cron string scheduling

[mfsiega-airbyte]

What

Include a list of available timezones for cron string scheduling in the frontend.

How

• Added a log line in the server (which does the validation) to dump the available IDs in JSON
• Removed the Etc/ timezones, which we specifically filter out
• Pasted the output into the frontend package

Recommended reading order

1. airbyte-webapp/src/config/AvailableTimeZones.json

🚨 User Impact 🚨

No

[mfsiega-airbyte]

This is the lightest-weight solution to unblock frontend work on the scheduling UX.

Some additional possible testing:

• Put this file in some common location between server and webapp
• Add a test in the server package that checks that every timezone in the list is still available.

This can either be added to this PR or done in a follow-up.

Further possible step: generate the list dynamically in the build process.

[timroes]

Could we maybe name the file lowercase. Despite some other files in this folder, this is kind of the standard we're going for, if it's not a component/class.

Also maybe we can include that it's about cron, e.g. availableCronTimeZones.json?

[mfsiega-airbyte]

Updated, please take a look!

[timroes]

LGTM