WiFiGeneric CrashFix v2.x

[mrengineer7777]

Description of Change

This PR resolves crashes in WiFiGeneric.cpp. The crashes can occur with CORE_DEBUG_LEVEL >= 2.
Targeting branch v2.x

Observed:

• Crash due to bad index into system_event_reasons[].

Potential:

• Crash on bad index into arduino_event_names[]. e.g. New entry added but string array not updated.
• Crash if event is null.

Changelog:

• Replaced arduino_event_names[] with WiFi.eventName().
• Replaced system_event_reasons[] and reason2str() with WiFi.disconnectReasonName().
• Return if event is null.

Advantages:

• Easier to maintain string conversions when types are updated.
• Users can call WiFi.eventName() and WiFi.disconnectReasonName() for their own use.
• Codespace is only used if the function is called.
• Functions return blank strings rather than crashing when an unknown type is encountered.
• disconnectReasonName() can be modified to work with multiple Arduino versions by using conditional compiles.

Observations:

• Several additions on wifi_err_reason_t.
• No changes on arduino_event_id_t.

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Tests scenarios

Tested on custom hardware (ESP32-WROOM-32UE module) with arduino-esp32 v2.0.7. Works on both WiFi and Ethernet events. Functions are being used in our latest production firmware.

Related links

Closes #7959