FilenameGenerator Sampler Scheduler

[w-e-w]

Description

• [Feature Request]: Add a scheduler pattern to the filename save options now that it has been removed from the sampler in 1.9.0 #15578

the behavior of the FilenameGenerator pattern [sampler] was change in 1.9 due to

• Scheduler selection in main UI #15333

this PR add an adds two new FilenameGenerator pattern

• [sampler_scheduler]
  this is basically the old behavior {Sampler} {Scheduler} ie DPM++ 2M Karras
• [scheduler]
  only {Scheduler} part ie Karras

note for some samplers automatic scheduler I wasn't able to find a corresponding type and so they will be output as Automatic
not sure if they should be displayed as blank

Debate

should the old behavior of [sampler] be restored
if so [sampler_scheduler] will be renamed to [sampler] and [sampler] rename to [sampler_only] or something similer

reason to restore: preserve old behavior
reason not to restore: [sampler] and [sampler_scheduler] is more straightfor

Checklist:

• I have read contributing wiki page
• I have performed a self-review of my own code
• My code follows the style guidelines
• My code passes tests