Drawer menu implementation

[AndyScherzinger]

This PR is a new take (compared to #198) on implementing the drawer menu (basically what I implemented on the Nextcloud client and Nextcloud SMS client itself).
Due to my IDE setup this PR will also update the build tools used, the gradle wrapper and the Android gradle plugin version too. So this PR needs Android Studio 3.0.1 to work. If this is a problem than I can revert back the files that lead to this (their are not necessary for this PR but have been auto-updated by Android Studio 3.0.1).

This PR adds a Drawer Implementation to the main view of the app adding

• 3 menu items via a menu configuration file
• adding an abstract DrawerActivity which takes care of the drawer handling (screen rotation state preservation, menu icon tinting, etc.)
• it doesn't add a "favorites" item since I haven't seen this functionality yet but that would be easy to do - once the functions is available one just needs to add another menu items + action.

Here are 2 screenshot of how it looks on Android 8 (and since it is implemented with the standard appCompat classes it also looks like this on older Android versions :)

Please let me know if anything needs to be changed and don't hesitate to ask any questions that might come up.

cc @jancborchardt @korelstar @stefan-niedermann 😀

Hope you like my work ❤️

[AndyScherzinger]

Pinging @korelstar @stefan-niedermann for review / feedback :)

[korelstar]

Sorry, this month (and I think also the next one) I have no time for this project. But after that, I'll be back ;-)

Nevertheless, I've noticed your PR and I thank you very much for your contribution. However, I'm very confused about it, since we've introduced the NavigationDrawer already in #275 (it was merged into master some time ago (before your PR) but there isn't any new release with it yet). Therefore, #198 is obsolete and should be closed. Hence, I think your work is also already obsolete (I assume that you hadn't seen the process in master) -- I'm very sorry to say that. On the other hand, maybe there are some aspects of your implementation that we should integrate into the current solution?

[AndyScherzinger]

@korelstar thanks for the feedback. I missed #275 and only saw #198. Looking at #275 it seems to me that one already implements anything which this PR would have added. So it can likely be closed.