check MAX_ACCOUNT_NAME_LENGTH in all requests

[zheng yin]

MAX_ACCOUNT_NAME_LENGTH is configurable and therefore could be changed, and made smaller, during the life of a cluster. That means there could be account names that exist in a cluster that are longer than the current constraint but can be accessed with GET/HEAD/POST。
Therefore, it only checks account name length in PUT.

[Thiago da Silva (thiagodasilva)]

MAX_CONTAINER_NAME_LENGTH is currently checked in GET/HEAD/POST/PUT, it should definitely remain in PUT and POST, but it is not clear why it was added for GET/HEAD, maybe someone with more history knows and can make an argument for keeping/removing.

[Thiago da Silva (thiagodasilva)]

This is a conversation we had about this bug:

http://eavesdrop.openstack.org/irclogs/%23openstack-swift/%23openstack-swift.2017-08-31.log.html#t2017-08-31T19:30:58

[John Dickinson (notmyname)]

the fix is to move the constraint check (see the IRC conversation), and this is correctly categorized as low priority