Add the ability to select a sequence template from the framing wizard

[Ara Jerahian]

Currently, the framing wizard uses the sequence template as defined in the options. This is great, but it limits the user to one sequence template for all targets generally, unless you go and change the option to select a different one.

As an alternate approach, it would be a good idea to add the ability to select a sequence template from the framing wizard itself. The sequence template logic could scan a specific directory (the directory would be set in the options instead of the template itself) and list all the different sequences as options in the dropdown (probably by filename). That way, I can have a sequence template for NB targets, a template for LRGB targets, a template for HaLRGB targets, etc. This would be a really nice addition to quickly create multi-panel mosaics, as well as anywhere else from which one would automatically create/add a sequence target.

[Stefan B]

1.11 allows for selection of sequencer2 DSO templates for different purposes.