Enable tier sorting/ordering in places where there is none yet

[ocrasborn]

• Over the years, A-Z sorting buttons have appeared in some dialogues but not others. Add.
• Consider option of sorting by hierarchy, participant, annotator in various places -- as available in timeline now --> Postpone this until later.

[ocrasborn]

Not yet sortable nor sorted alphabetically by default* ($ after an item indicates first priority)

• File > Multiple File Processing > Edit multiple files $
• File > Multiple File Processing > Statistics for multiple files $
• File > Multiple File Processing > Annotations from overlaps $
• File > Multiple File Processing > Annotations from subtraction $
• File > Multiple File Processing > Calculate Inter-annotator Reliability $
• File > Export Multiple Files > Tab-delimited text
• File > Export Multiple Files > Selected tiers as EAF $
• File > Export Multiple Files > As list of words
• File > Export Multiple Files > As list of annotations
• File > Export As > Tab-delimited text
• File > Export As > Quicktime text
• File > Export As > Subtitles
• File > Export As > List of words
• File > Export As > Tiers for recogniser
• File > Merge Transcriptions... $
• Tier > Change Tier Attributes $
• Tier > Change parent of tier
• Tier > Delete tier
• Tier > Import tiers $
• Type > Change Linguistic Type
• Search > Find and replace in multiple files $
• View > Tier dependencies
• View > Annotation statistics $
• Grid viewer / Text viewer / Subtitles viewer $

*Often, tiers seem to be sortable or even sorted alphabetically, but then there's often the 'Example' tier dangling at the bottom. (the difference between Create Annotations From Overlaps and Create Annotations From Overlaps (Classic) is a good example)