How to read USB mouse data using STM32f103C OTG USB functionality?
Unfortunately STM32F103 series do not have OTG_FS hardware. Reference manual is misleading as it mentions both OTG_FS and USB Device modules. This is because some parts in this family have it (like STM32F105). You can use STM32CubeMX to find a microcontroller by filtering them according to selected criteria.

A framework based on ArduinoIDE is probably not the best approach for developing a USB host application. I suggest starting with STM32Cube examples. I haven't tried it myself, but STM32CubeMX seems to be able to generate USB Host HID class code.