Add littlefs file system and update Sys.IO.FileSystem and stream #179

Job	Run time
build-target (SL_STK3701A, Debug, AzureRTOS)	2m 52s
build-target (SL_STK3701A, Debug, All)	7m 42s
build-target (ST_STM32F769I_DISCOVERY, Debug, ChibiOS)	3m 57s
build-target (ST_STM32F769I_DISCOVERY, Debug, All)	7m 47s
build-target (M5Core2, Debug, ESP32)	5m 45s
build-target (M5Core2, Debug, All)	8m 5s
build-target (NXP_MIMXRT1060_EVK, Debug, FreeRTOS-NXP)	3m 16s
build-target (NXP_MIMXRT1060_EVK, Debug, All)	6m 42s
build-target (TI_CC1352R1_LAUNCHXL, Debug, TI, 915)	2m 37s
build-target (TI_CC1352R1_LAUNCHXL, Debug, All, 915)	6m 22s
	55m 5s

Provide feedback