Add endpoint to check if user has access to a given workspace host for Workspaces HTTP Server

MR: Add internal API endpoint for workspace authori... (!203350 - merged) • Chad Woolley • 18.4

Description

As part of protecting all workspaces traffic by OAuth, we need an authorization endpoint in Rails which will take the user_id and workspace_host(e.g. 123-ws1.workspaces.example.com) as inputs, return if the user has access to that given workspace(ws1). The response would be as follows

If user is accessing 123-ws1.workspaces.example.com (where the workspace with name ws1 has id 1), the response would be -

status: AUTHORIZED
info:
  workspace_id: 1
  workspace_port: 123

Scenarios where either the workspace is not found or port is not found or user is not authorized.

status: WORKSPACE_NOT_FOUND / PORT_NOT_FOUND / NOT_AUTHORIZED
info: {}

Acceptance criteria

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• [Describe what must be achieved to complete this issue.]
• [If applicable, please provide design specifications for this feature/enhancement.]
• [If applicable, please list any technical requirements (performance, security, database, etc.)]

Implementation plan

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