[desktop] Add managed resources as a GPO feature

[mattermod]

in the next version, managed resources will be a feature that can be enabled by configuring buildconfig.js and adding the paths you need and then recompile which is cumbersome. For a windows-only environment, we could add this feature as a GPO template so no compile step is needed.

Docs about managed resources: https://github.com/mattermost/docs/pull/3720/files

PR for managed resources: https://github.com/mattermost/desktop/pull/1311

GPO templates: https://github.com/mattermost/desktop/tree/master/resources/windows/gpo

Registry management code https://github.com/mattermost/desktop/blob/master/src/common/config/RegistryConfig.js

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JIRA: https://mattermost.atlassian.net/browse/MM-27289