OAuth Authorization code flow for setting up google calendar

[Shivam60]

Current process for setting up google calendar is very tedius even for developers. It also does not explain why redirect url to obsidian calendar app is required. It also instills no confidence as to how this permission wont be misused

Proposal: Set up authorization code flow with google calendar. Document short comings if any to inspire confidence.

[YukiGasai]

Hi, the plugin is using OAuth code flow. But because the Google Cloud Application has Request limits everyone has to create an own Client + I don't want to share a client secret in the public code.

If you want to read more about a my ideas for authorization I wrote my bachelors thesis (German) about a possible solution for a public client.

Bachelorarbeit.pdf