[ENHANCEMENT] Molecule viewer tab

[oerc0122]

Is your feature request related to a problem? Please describe. Currently the only place to view molecules is if a task has a single molecule selector (Infrared/ReorientationalCorrelation).

Describe the solution you'd like In the trajectories loader/viewer another tab (along the lines of #1024) to select, view and maybe build molecules (based on SMARTS selection)?

Describe alternatives you've considered N/A

Additional context N/A