test/py: gpt: test start LBA for sub-command rename and swap

Add test of first and last LBA in gpt for rename and swap.
Only the name is expected to change, so test 3 columns
for part command
1: first LBA (start)
2: last LBA (end)
3: partition name

After rename, the last LBA change and it is a error in current U-Boot code
+ "first" = 0x7ff : invalid value (<start)
+ "second" = 0x17ff => size increasing !

Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>