feat: add STM32WL3x support (experimental)

[fpistm]

This PR add the support of the STM32WL3 series.

• From STM32CubeWL3 v1.2.0
  • Add HAL from version 1.2.0
  • Add CMSIS from version 1.2.0

Warning

No test done only build.

Closes #2643.

[Copilot]

Pull Request Overview

This PR adds experimental support for the STM32WL3 series microcontrollers based on STM32CubeWL3 v1.2.0, introducing HAL and CMSIS drivers. The implementation focuses on build compatibility with no functional testing performed.

• Adds comprehensive HAL driver headers for STM32WL3x peripheral support
• Introduces power management, RF (MRSUBG), and low-power wakeup (LPAWUR) modules
• Provides GPIO, communication (I2C, SPI, UART), and timer functionality

Reviewed Changes

Copilot reviewed 146 out of 295 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
stm32wl3x_hal_pwr_ex.h	Extended power management module with SMPS, GPIO retention, and deep stop features
stm32wl3x_hal_pwr.h	Core power management with PVD, wakeup sources, and power mode definitions
stm32wl3x_hal_mrsubg_timer.h	RF timer management for MRSUBG IP with virtual timer support
stm32wl3x_hal_mrsubg.h	Sub-GHz radio (MRSUBG) HAL driver with packet handling and sequencer control
stm32wl3x_hal_lpawur.h	Low-power wakeup receiver (LPAWUR) HAL driver
stm32wl3x_hal_lcd.h	LCD controller HAL driver with comprehensive display management
stm32wl3x_hal_iwdg.h	Independent watchdog HAL driver
stm32wl3x_hal_irda_ex.h	Extended IRDA HAL module with word length definitions
stm32wl3x_hal_irda.h	IRDA communication HAL driver
stm32wl3x_hal_i2s.h	I2S audio interface HAL driver
stm32wl3x_hal_i2c_ex.h	Extended I2C features including analog filter and fast mode plus
stm32wl3x_hal_i2c.h	I2C communication HAL driver
stm32wl3x_hal_gpio_ex.h	GPIO extended features with alternate function mappings
stm32wl3x_hal_gpio.h	GPIO HAL driver with EXTI support
stm32wl3x_hal_flash_ex.h	Extended FLASH operations including OTP and page protection

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