ZCS-2691 Create DataSource implementation for LinkedIn contacts via oAuth

[chinmay15]

Problem/Task: create datasource implementation for Linkedin contacts sync using oAuth2

Fix:

1. Authorize and authenticate using oAuth2 rest api provided by Linkedin
2. Folder created is with name as -contact-linkedin, as profile call for linkedin needs "r_fullprofile" permission and this permission in given by linkedin on request. Request with linkedin support is raised.

Testing done:

1. Contact folder and datasource is created in user account.
2. Tested functionality manually.

zmprov gds cp1
# name [email protected]
# type oauth2contact
objectClass: zimbraDataSource
zimbraCreateTimestamp: 20180724133602.672Z
zimbraDataSourceConnectionType: cleartext
zimbraDataSourceEnabled: TRUE
zimbraDataSourceFolderId: 60020
zimbraDataSourceHost: www.linkedin.com
zimbraDataSourceId: 54e84c2e-50e5-405f-aa60-9c008d41aac0
zimbraDataSourceImportClassName: com.zimbra.oauth.handlers.impl.LinkedinContactsImport
zimbraDataSourceImportOnly: FALSE
zimbraDataSourceName: [email protected]
zimbraDataSourceOAuthRefreshToken: VALUE-BLOCKED
zimbraDataSourcePollingInterval: 1d
zimbraDataSourceType: oauth2contact

Testing needs to be done by QA:

1. go to https://www.linkedin.com/developer/apps
2. create app from - my apps -> create app
3. select default app permissions "r_basicprofile" and "r_emailaddress"
4. add "https://<your_host_name>/service/extension/oauth2/authenticate/linkedin" OAuth 2.0 authorized redirect url
5. set zimbraOAuthConsumerRedirectUri: https://cpathak.zdev.local/service/extension/oauth2/authenticate/linkedin:linkedin
6. set zimbraOAuthConsumerCredentials: <app_client_id>:<app_client_secret>:linkedin
7. Make sure, Authorization and Authentication is done using oAuth2
8. Make sure, contacts folder and datasource is created as mentioned above

Linked PR:
Zimbra/zm-oauth-social#44

[desouzas]

Prashant said we were going to put LinkedIn aside for now.

If we're adding them all, please add twitter.

e: Just noticed the date on this haha.