Add DMA and LiquidCrystal I2C support

- Implemented DMA functionality with a new dma.c and dma.h file.
- Added LiquidCrystal I2C driver with liquidcrystal_i2c.c and liquidcrystal_i2c.h files.
- Updated CMakeLists.txt to include dma.c and liquidcrystal_i2c.c in the build process.
- Modified build.ninja and compile_commands.json to reflect the new source files.
- Enhanced the main application to utilize the new DMA and LiquidCrystal I2C features.

Core/Src/stm32f1xx_it.c

@@ -55,7 +55,8 @@
 /* USER CODE END 0 */
 
 /* External variables --------------------------------------------------------*/
-extern I2C_HandleTypeDef hi2c1;
+extern DMA_HandleTypeDef hdma_usart2_rx;
+extern DMA_HandleTypeDef hdma_usart2_tx;
 extern UART_HandleTypeDef huart1;
 extern UART_HandleTypeDef huart2;
 /* USER CODE BEGIN EV */
@@ -201,17 +202,31 @@ void SysTick_Handler(void)
 /******************************************************************************/
 
 /**
-  * @brief This function handles I2C1 event interrupt.
+  * @brief This function handles DMA1 channel6 global interrupt.
   */
-void I2C1_EV_IRQHandler(void)
+void DMA1_Channel6_IRQHandler(void)
 {
-  /* USER CODE BEGIN I2C1_EV_IRQn 0 */
+  /* USER CODE BEGIN DMA1_Channel6_IRQn 0 */
 
-  /* USER CODE END I2C1_EV_IRQn 0 */
-  HAL_I2C_EV_IRQHandler(&hi2c1);
-  /* USER CODE BEGIN I2C1_EV_IRQn 1 */
+  /* USER CODE END DMA1_Channel6_IRQn 0 */
+  HAL_DMA_IRQHandler(&hdma_usart2_rx);
+  /* USER CODE BEGIN DMA1_Channel6_IRQn 1 */
 
-  /* USER CODE END I2C1_EV_IRQn 1 */
+  /* USER CODE END DMA1_Channel6_IRQn 1 */
+}
+
+/**
+  * @brief This function handles DMA1 channel7 global interrupt.
+  */
+void DMA1_Channel7_IRQHandler(void)
+{
+  /* USER CODE BEGIN DMA1_Channel7_IRQn 0 */
+
+  /* USER CODE END DMA1_Channel7_IRQn 0 */
+  HAL_DMA_IRQHandler(&hdma_usart2_tx);
+  /* USER CODE BEGIN DMA1_Channel7_IRQn 1 */
+
+  /* USER CODE END DMA1_Channel7_IRQn 1 */
 }
 
 /**