Updated Deprecated Endpoints

[Pratheek555]

Brief Title

Updated the endpoints which were found to be deprecated from the docs.

Fixes #1034

What are the changes made?

• endpoint changed from getUserRoles --> /roles.getUsersInPublicRoles
• /api/v1/method.call/rooms%3Aget endpoint which was used to get info of a room using DDP was found to be deprecated, therefore we are using a REST api endpoint which does the same thing.

PR Test Details

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