Filesystem improvements and more (#148)

- Rename `assets` and `config` partitions to `system` and `data`
- Change partition type from `spiffs` to `fat`, so we can have sub-directories
- Fix crash when doing WiFi scan: Increased system event task size to 3kB. 
- Free up IRAM on ESP32 (it was required for the Core2, but I also freed up the same amount for Yellow Board)
- Introduced `Paths` objects that can be retrieved by `AppContext` and `ServiceContext`. Apps and services now have their own relative paths. Assets were re-arranged into the correct paths.
- Rename simulator window title to "Tactility"
- Refactored statusbar widget so it persists icon paths properly (it kept a const char* reference, but didn't copy it, so it crashed when the related std::string was destroyed)
- Created `Partitions.h` to expose some useful variables
- Moved USB config in various `sdkconfig`  (it was part of the "default" section, but it shouldn't be)
- Updated domain name

Documentation/ideas.md

@@ -10,6 +10,7 @@
   - Show error in WiFi screen (e.g. AlertDialog when SPI is not enabled and available memory is below a certain amount)
 - Clean up static_cast when casting to base class.
 - M5Stack CoreS3 SD card mounts, but cannot be read. There is currently a notice about it [here](https://github.com/espressif/esp-bsp/blob/master/bsp/m5stack_core_s3/README.md).
+- SD card statusbar icon shows error when there's a read timeout on the SD card status. Don't show the error icon in this scenario.
 
 # TODOs
 - Call tt::lvgl::isSyncSet after HAL init and show error (and crash?) when it is not set.