Update SBML to 5.19

[tpfau]

Update SBML to 5.19, This should fix some issues during IO.

I hereby confirm that I have:

• [X] Tested my code on my own machine
• [X] Followed the guidelines in the Contributing Guide
• [X] Selected develop as a target branch (top left drop-down menu)

(Note: You may replace [ ] with [X] to check the box)