Improved NestBot /events command

[abhayymishraa]

Resolves #641

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Task Completed:

• Improved /events slack command
• Added get_events_data() in utils to fetch data from the source file
• Added testcases for it (covers 96%)

Preview/ScreenShots:

Slack:

TestcaseCoverage:

[abhayymishraa]

After this commit:

• Added command to populate database
• Added graphql (Query/Node) for event model
• Added NestBot command /events to fetch data from directly from graphql (internally)
• Extended Event Model to include new changes
• updated testcases as per new chnages
• Sorted the events with the StartDate

Chnages Look Like:

[abhayymishraa]

• Removed event sync logic as it's of no use

[abhayymishraa]

hey @arkid15r , i removed the syncing lofgic for removing any data once it will be removed from the data then we can remove the fields that were previously used by them