feat(device provisioning): Implement Improv Wi-Fi protocol using serial interface (Wi-Fi config via web installer)

[Slider0007]

⚠️ This feature set will be only available using firmware release v17.0.0 and newer ⚠️

---

Implement Improv Wi-Fi protocol using a serial port to enhance the web installer functionality, which is already available for this repo to install firmware using a web interface.

Benefits:

• Set up WLAN connection using web installer (incl. WLAN network scan) -> No need to switch to device access point network
• Jump directly to device (e.g. no need to figure out IP address)
• Show firmware information

--> This allows using an additional alternative device provisioning workflow described below

---

Additional alternative device provisioning workflow

Workflow Step 2: Initial connection to flash firmware

Workflow Step 4: Connection to device with firmware flashed, but no WLAN configured yet

Workflow Step 4.1: Scan for WLAN networks

Workflow Step 5: Connection to device

Workflow Step 6:

Workflow Step 7:

Workflow Step 8:

---

Implementation is inspired and derived from https://github.com/improv-wifi/sdk-cpp and https://github.com/jnthas/Improv-WiFi-Library.

---

Usage before:
RAM: [= ] 13.9% (used 45520 bytes from 327680 bytes)
Flash: [========= ] 85.6% (used 1665441 bytes from 1945600 bytes)

Usage after:
RAM: [= ] 13.9% (used 45664 bytes from 327680 bytes)
Flash: [========= ] 86.6% (used 1684381 bytes from 1945600 bytes)