Release Branch v1.3.0

[RobertByrnes]

• Feature flag for compatibility with MbedTLS v3.x.x - Automated by MBEDTLS_VERSION_MAJOR.
• Add Flag MBEDTLS_BACKPORT to allow override MBEDTLS_VERSION_MAJOR >= 3.
• Add workaround for W5500 Ethernet failing due to client returning -1 when no error - switch on flag W5500_WORKAROUND.
• close Support for ESP32 and W5500 based Secure Ethernet for HTTPS or MQTTS? #44 close SSLClient with W5500 not working (works well with WiFi and TinyGSM) #85.
• Improve documentation.
• Add GitHub Actions workflow to ensure PlatformIO examples compile.
• Update GitHub Actions workflow to run tests multiple times with feature flags set.
• Add GitHub Actions workflow to ensure Arduino IDE compile.
• Fix Arduino IDE examples to compile when using arduino-esp32 @2.0.17 - This is still broken for @3.0.2 There is a breaking change in arduino-esp32 from v3.0.0 which is causing ambiguous reference errors to byte.