HPCC-11620 Return permission list for current user

This fix upgrades ws_access.AccountPermissions to return
permission list for corrent user. If the AccountName in
AccountPermissions request is not set, the UserID with
that request is used as the AccountName for retrieving
the permission list for the corrent user. The current
user does not have to be an admin.

Signed-off-by: wangkx <kevin.wang@lexisnexis.com>
Merge pull request #6219 from wangkx/h11620

HPCC-11620 Return permission list for current user

Reviewed-By: Gordon Smith <gordon.smith@lexisnexis.com>
Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>