Refactoring: Modularity and best practices

[aceisace]

Currently, there is no differentiation between Inkycal's built-in modules and requirements and those of third-party extensions.
This leads to problems with dependencies when installing Inkycal.
A better approach is to organise modules in the following way:

• inkycal/modules/built-in/.. for built-in modules. The requirements from these is mandatory for installing Inkycal.
• inkycal/modules/third-party/.. for third-party modules.

Furthermore, each module should have it's own folder containing the following:

• __init__.py
• requirements.txt
• LICENSE
• Unittest for WEB-UI and module itself
• optionally any additional files it needs, e.g. additional functions

The aim for this is to make maintenance and testing much easier. Since modules can be tested independently from each other and errors can be narrowed down further. Additionally, it allows adding modules as easy as navigating to the third party folder and running git clone <url/to/inkycal_third_party_module>

TODO:

• Create layout-generator class to create layouts for modules. This should contain functions to write text in rows, columns and the specified channel
• Add support for pre-defined colour channels. Currently, 7 channels should be supported (ACeP), one for each colour band
• Shift built-in modules to built-in modules folder
• Create folder for third-party modules
• Add unittests in each module and rename tests according to best-practices, starting with test_..
• The current setup to load data in the web-ui from the required_parameters and optional_parameters field makes it difficult to enforce type enforcement, to add default parameters and to expand a field with multiple fields, e.g. adding an icon for each calendar. An alternate approach is docstrings or a separate config file, which would help solve these problems.
• Refactor display class to be non-blocking or stop automatically after n-seconds if there has not been a response from the display
• Add splashscreen before first rendering to show that Inkycal is actually running, independently from other modules.