VMware: Remove class orphaned by ESX driver removal

HostState was only used by the ESX driver, which was removed in
change I718fc0ee67dbd625af00c20fa4e34b8a35015437.

Also remove LOG, which is no longer used following previous removals.

Change-Id: I22e30c01e5b5219df858219dc1fda335a83ad225
VMware: Remove VMwareImage.file_size_in_gb

file_size_in_gb was rounding down. This is counter intuitive, as a
512MB disk is reported as 0GB. However, this rounding weirdness was
required for correctness in a way which wasn't obvious. When we test
if an image needs to be resized, we test instance.root_gb >
image.file_size_in_gb. Because file_size_in_gb was rounded down, an
image slightly smaller than 1GB will be reported as 0GB and therefore
resized.

The source of the rounding confusion is the bytes->gb conversion. To
make the code more obviously correct, I have switched it to instead
convert gb->bytes, which does not involve rounding. To ensure this
never trips anybody up, I have removed file_size_in_gb.

Change-Id: I99d20e3b1383e29cddff3d1016c4bcedc1683c4d
Remove the nova-manage flavor sub-command

The nova-manage flavor sub-command was deprecated in Juno milestone-1
via commit a601556684f18059e478ba645aff8276c9c78a4a with a note that it
will be removed in Kilo.

This removes it.

Change I4e2399f2fbab2c20299dd62c104b9220c1d36fb2 is to remove the
related Tempest tests.

Change-Id: I1798c8a0697009b3dcebeb818580c8323880e395
Merge "Remove the nova-manage flavor sub-command"
Merge "VMware: Remove VMwareImage.file_size_in_gb"
Merge "VMware: Remove class orphaned by ESX driver removal"