No 0-padding on track numbers in rename function

[Eric Bocelle]

Usually, track numbers as they appear in audio file names are 0-padded on 2 characters, like 01, 02, 03, ...
The metadata for track number might be some text already including this padding, but most of the time it simply is the "raw" track number (1,2,3, ...) converted to text (that's the case when entered or edited through the "Basic" tab).
My suggestion would be to convert the content of the field to integer and repad it systematically on 2 characters for the {trackNumber} placeholder
Maybe some users will have the usage of the raw text field, why not create a new placeholder {trackNumberText} for them ?