New code organization [#3169638]

Service CmisConnectionFactory
- getConnection($config_id) : CmisConnection
Class CmisConnection
- $config_id as attribute to get repository ID, folder ID, etc.
- method to obtain a CMIS session for GET requests
- method to obtain a CMIS session for POST requests
- checkConnectionIsAlive: to improve , see also #3162184: checkConnectionIsAlive: fire event
Class CmisHelper with only static methods
- getObjectById
- validObjectId
- validObjectName
- hasAllowableActionById
CmisRepositoryController -> CmisController
- getProperties
  - No more call the browser
  - Return directly renderable array with #theme cmis_content_properties
  - Change the theme key to have the variables config_id and object
  - Keep the big part of the implementation to the hook_preprocess so it will be overridable
- objectDeleteVerify:
  - Ok, to improve, especially translations and no more use a specific theme key
- objectDelete:
  - Ok, to improve
- Access:
  - Ok
- initBrowser:
  - To put in the browse method, only keep one method
CmisBrowser:
- Remove the getDocumentProperties method
- ajaxCall: to put compatible with nojs and to move in the controller
- getDocument: to move in CmisHelper and use it in the controller
- Browse -> getBrowserHtml
- prepareOperations: rework route management. No more render(). Handle destination parameters to manage redirections.
- printFolderContent -> getFolderContent
- setBreadcrumb -> getBreadcrumbLink
- setBreadcrumbs -> prepareBreadcrumb
CmisElement -> CmisBrowserElement:
- Remove the different theme keys (cmis_browser_folder_item, cmis_browser_document_item, cmis_browser_other_item) and only keep one with the variables, the CMIS object's title, the Mime type, and/or the CMIS object directly. And prepare the link with a preprocess. So it will be overridable and for example we will be able to make a sub-module for some basic icons support (#3162831: Improve UX).
- Remove the render() to at the end keep a big renderable array that will be alterable
- Rework the constructor arguments order
- format_size
Service CmisHelper
- getDocument
- Cmis_get_configurations