[Feat] Notion Authorization with Rocket.Chat

[Nabhag8848]

Issue(s)

• Closes [Feat] Notion Authorization with Rocket.Chat #4

Acceptance Criteria fulfillment

• Create Setting for Credentials (SettingType STRING - ClientId, SettingType PASSWORD Client Secret).
• Register Command with params connect and disconnect.
• Create NotionSDK Class
• Create WebHookEndpoint for handling Notion Callback
• Create Function to getTokenInfo else Send Relevant Notification with Connect to Workspace button alerting user not connected.
• Send Relevant Notification to Channel including Message from MessageBuilder when there is complete execution.
• Create MessageBuilder with Button (only in case of connect)

Proposed changes (including videos or screenshots)

Further comments

• Create CustomError Class extending which have CommonError class
• Use Integration SVG in Authorization HTML page.
• Handle Empty Credentials and give Notification to channel as per user Roles.

Edge Cases

• When User Changes State in AuthURL
• When User Leaves in Between Auth
• When User Cancel the Auth but Go Back to AuthURL pressing <— in Browser
• When User runs connect command in two channels [Say first and Second] one by one during session and connects from First Message should go to First and so on.
• When There is Problem from Notion Provider to Generate Token
• Using feat with multiple user.
• Handle Empty Credentials and give Notification to channel as per user Roles.

[samad-yar-khan]

LGTM @Nabhag8848