* iterators for random-access MolSuppliers
add optional caching to SDMolSupplier
* add support to SmilesMolSupplier too
There is a lot of duplicate code between the random-access suppliers that would be worth trying to remove
but at the moment it looks like it would require multiple inheritance, and I think we want to avoid that
* add input iterators for ForwardSDMolSupplier()
* throw when calling begin() on a used supplier
* switch to use the spaceship operator
* init() should reset the mol cache
* Make SDMolSupplier and SmilesMolSupplier safe for multi-threaded reads
* add benchmarking
* add TDTMolSupplier support
improved testing
add benchmarks for parallel iteration
optional TBB support
* better const handling, add reverse iterators
doesn't look like const_iterator is possible since getting data from the underlyng supplier object is non-const
* improve docs
more usings
add reverse iterator to TDTMolSupplier
* tests only try execution::par when it is there
* fix typo
* more testing/demo
* remove accidentally added files
* review changes
* add default ctors
* disable a false-positive compiler warning
it is stupid to have to do this
---------
Co-authored-by: = <=>
