Fixes inconsistencies and adds extended HardwareSerial examples

[SuGlider]

Description of Change

This PR adds some examples that use API extensions to HardwareSerial, implemented to better controls UART communication using ESP32 Arduino.

HardwareSerial changes:

UART FIFO Full will depend on the baud rate.
For lower or equal to 57600 baud, it will force to emulate byte-by-byte reading on UART ISR.
For higher baud rate, it will keep IDF default of 120 bytes for FIFO FULL Interrupt.
The FIFO Full parameter can also be changed by the application at any time using HardwareSerial::setRxFIFOFull(uint8_t fifoBytes)

It also fixes some inconsistencies found when using the examples.

• When Rx timeout is Zero (disabled), there is only one possible option which is execute the callback when FIFO reaches 120 bytes
• In case that onReceive() shall work only with RX Timeout, FIFO shall be high. This is a work around for an IDF issue with events and low FIFO Full value (< 3)

Tests scenarios

The examples have been tested using ESP32, ESP32S2, ESP32S3 and ESP32C3.

Related links

#6921
#6689
#6849

[Jason2866]

The headline is missleading. It is not just adding examples.

[SuGlider]

@me-no-dev @P-R-O-C-H-Y
This PR is ready for your review. Thanks!