One more thing. 

When I right click uint32_t and click "go to definition"

It brings me to "core_cm4.h"

And this is the code it is pointing to:
Code (C++):

/**
  \brief   ITM Send Character
  \details Transmits a character via the ITM channel 0, and
           \li Just returns when no debugger is connected that has booked the output.
           \li Is blocking when a debugger is connected, but the previous character sent has not been transmitted.
  \param [in]     ch  Character to transmit.
  \returns            Character to transmit.
 */
__STATIC_INLINE uint32_t ITM_SendChar (uint32_t ch)
{
  if (((ITM->TCR & ITM_TCR_ITMENA_Msk) != 0UL) &&      /* ITM enabled */
      ((ITM->TER & 1UL               ) != 0UL)   )     /* ITM Port #0 enabled */
  {
    while (ITM->PORT[0U].u32 == 0UL)
    {
      __NOP();
    }
    ITM->PORT[0U].u8 = (uint8_t)ch;
  }
  return (ch);
}

 

I tried this again but this time looked for errors in the Errors List. I could see nearly 2000 in VS2017 and 1500 in VS2019. All the false errors related to the underlying core not my own project code.

I then click "vMicro>Show Hidden Files" which is recommended for better F12 GoTo Definition anyway. Then the error list reduced to 3 errors without need to filter the Error List for "Open Documents" or "Build Only".