[Feature Request] Add help text about disk space units (binary vs decimal) to "Create New Partition Table" dialog

[Nokhrin]

Problem

Users may be confused by disk size units in the partitioner. The interface does not clarify that partitioning uses binary units (GiB) rather than decimal units (GB), which can lead to unexpected available space calculations.

Proposed Solution

Add a help text note to the "Create New Partition Table" dialog (accessible via Expert -> Create New Partition Table when a disk is selected in the Expert Partitioner) explaining the unit difference.

Suggested Text

Note that for partitioning purposes, disk space is measured in binary units, rather than in decimal units. For example, if you enter sizes of 1GB, 1GiB or 1G, they all signify 1 GiB (Gibibyte), as opposed to 1 GB (Gigabyte).

Binary
    1 GiB = 1 073 741 824 bytes. 
Decimal
    1 GB = 1 000 000 000 bytes. 
Difference
    1 GiB ≈ 1.07 GB.

Reference

This text matches the documentation format at:
https://doc.opensuse.org/documentation/leap/reference/html/book-reference/cha-expert-partitioner.html#_warning_disk_space_units