Enabled scalefactor and improved text readout for Identifier tool

[jtroberts]

Purpose

• Improvements to the Identifier tool to allow a scale factor for specified layers and better text alignment in data readouts.

  Proposed Changes

• Add support for a "scalefactor" Identifier tool variable.
• Change data readout when there is just a single band value.

  Issues

• Consistent text alignment in Identifier Tool readouts #555
• Apply scale factor to Identifier Tool source data readouts #556

  Testing

• Added scalefactor to a few layers and tested existing layers without new variable.
• Viewed text readouts to ensure data accuracy