Fixed coordinate precision for optimized svg

Steps to reproduce:

• Open any svg file.
• Scale and adjust the drawing dimension to be 1000 pixels wide.
• Save it as "Optimized SVG".
• In the first dialog setting, set the coordinate "precision" to 3.
• Open the resulting svg file with a text editor.

What happened?

Points near the origin (0,0) have a high precision, e.g. 9.45 The precision decrease as we reach the other side of the drawing, e.g. 869.

What should have happened?

The precision should be constant on the whole drawing. There is no point to have two decimals on one side of the drawing but no precision on the other side. The precision should be expressed as the number of decimal digits, not as the number of digits for the whole coordinate.

This would decrease further the file size which is the purpose of optimized svg.

Inkscape Version and Operating System:

• Inkscape Version: 92.3-2405546
• Operating System: Windows
• Operating System version: 10