Improve GUI for marketeer role

[bceyssens]

Here are some suggestions to make the GUI make userfriendly for marketeers:

• allow the API url to be passed via a query param so it is prefilled on the login form, eg.: https://tracardi-gui.environment.com/login?api-url=tracardi-api.environment.com
• hide menu items you don't have access to (resources, traffic, ...)
• improve the conditions interface for configuring segments. See Onesignal, Google Analyics or the widgets in Tracardi workflows. It would be nice to viualize the amount of profiles (or percentage) in the segment

[atompie]

@bceyssens We have role mechanism in place to hide some parts of the system depending on the user role. Soon we will implement it in the system.

[atompie]

I also looked for react field for conditions and soon we will make some available. Any way thanks for suggestions always interested in new ideas.

[DawidekZagajnik]

@bceyssens first part done, waiting for code review and merge by @atompie! works like http://localhost:8686/login?api_url=[host]

[DawidekZagajnik]

@bceyssens that's the idea for now:

only thing that's left in settings is event tags, and we are going to move it to management, so that's a "preview-prototype". Mechanism ready though