make throwing SBML load errors configurable

[CI] Use `julia-actions/cache` for caching

add functions that make it easy to get models from a url and sbml-test-suite

add convert_promote_expand

include ccov badge

`use_value_from_trigger_time` is semantically a Bool

support CV terms

(marks a feature)

(annotations are redundant in this case but we have to test if they get
recreated correctly, and if the CV terms survive even without the annotation
strings)

Fix backwards compatibility of `interpret_math` with Avogadroes

implement the special handling for avogadro constant

Co-authored-by: Mosè Giordano <giordano@users.noreply.github.com>

bump version to 1.2.0

cleanup&fix the sbmlRelational patch