Fix generation of kernel uevents for snapshot rename on linux

zvol_rename_minors() needs to be given the full path not just the
snapshot name. Use code removed in a0bd735ad as a guide
to providing the necessary values.

Add ZTS check for /dev changes after snapshot rename. After
renaming a snapshot with 'snapdev=visible' ensure that the /dev
entries are updated to reflect the rename.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: James Dingwall <james@dingwall.me.uk>
Closes #14223
Closes #16600