Setup ESP32 PM-specific capability flags

[m1nl]

1. Defined two ESP32-specific capability flags:

HAS_ESP32_PM_SUPPORT - set to 1 when ESP-IDF used to compile Arduino framework supports PM (power management) extensions
HAS_ESP32_DYNAMIC_LIGHT_SLEEP - set to 1 when ESP-IDF used to compile Arduino framework supports dynamic light sleep

2. Standarized value of HAS_32768HZ capability flag to 1 or 0 (with 0 value as default) to follow convention of other capability flags

3. Enabled HAS_32768HZ capability flag for Heltec V3 board (according the schematic, there is 32k XTAL connected to ESP32S3 chip)

Changes were tested with Heltec V3 board:

INFO  | ??:??:?? 0 No BLE OTA firmware available
INFO  | ??:??:?? 0 No WiFi OTA firmware available
DEBUG | ??:??:?? 0 Switch RTC Source to 32.768kHz succeeded, using 32k XTAL
INFO  | ??:??:?? 1 Init NodeDB

These changes are to streamline adoption of code changes requested in PR #7121 . Espressif documentation suggests that setting up 32768 Hz XTAL improves power saving and Bluetooth stability when dynamic light sleep is enabled.