Update properties parsing for app manifest and device manifest files (#544)

Devices/m5stack-cardputer-adv/device.properties

@@ -1,24 +1,19 @@
-[general]
-vendor=M5Stack
-name=Cardputer Adv
+general.vendor=M5Stack
+general.name=Cardputer Adv
 
-[apps]
-launcherAppId=Launcher
+apps.launcherAppId=Launcher
 
-[hardware]
-target=ESP32S3
-flashSize=8MB
-spiRam=false
-tinyUsb=true
-esptoolFlashFreq=120M
-bluetooth=true
+hardware.target=ESP32S3
+hardware.flashSize=8MB
+hardware.spiRam=false
+hardware.tinyUsb=true
+hardware.esptoolFlashFreq=120M
+hardware.bluetooth=true
 
-[display]
-size=1.14"
-shape=rectangle
+display.size=1.14"
+display.shape=rectangle
 # TODO: dps is actually 242, but this breaks UI (button selection becomes invisible and switch visibility is reduced)
-dpi=139
+display.dpi=139
 
-[lvgl]
-colorDepth=16
-uiDensity=compact
+lvgl.colorDepth=16
+lvgl.uiDensity=compact