Introduce the final accessor's to _virSecretObject data and move the
structure from virsecretobj.h to virsecretobj.c

The virSecretObjSetValue logic will handle setting both the secret
value and the value_size. Some slight adjustments to the error path
over what was in secretSetValue were made.

Additionally, a slight logic change in secretGetValue where we'll
check for the internalFlags and error out before checking for
and erroring out for a NULL secret->value. That way, it won't be
obvious to anyone that the secret value wasn't set rather they'll
just know they cannot get the secret value since it's private.

Introduce fetch and set accessor to the secretObj->def field for usage
by the driver to avoid the driver needing to know the format of virSecretObj

Move and rename the secretRewriteFile, secretSaveDef, and secretSaveValue
from secret_driver to virsecretobj

Need to make some slight adjustments since the secretSave* functions
called secretEnsureDirectory, but otherwise mostly just a move of code.

Move and rename secretDeleteSaved from secret_driver into virsecretobj and
split it up into two parts since there is error path code that looks to
just delete the secret data file

Move to secret_conf.c and rename to virSecretLoadAllConfigs. Also includes
moving/renaming the supporting virSecretLoad, virSecretLoadValue, and
virSecretLoadValidateUUID.

Add function to return counted listed of uuids to from the hashed secrets
object list. This will replace the guts of secretConnectListSecrets.

Add function to return a "match" filtered list of secret objects. This
function replaces the guts of secretConnectListAllSecrets.

Need to also move and make global virSecretUsageIDForDef since it'll
be used by both secret_driver.c and secret_conf.c

Add function to count the hashed secret obj list with filters. This
will replace the guts of secret_driver's secretConnectNumOfSecrets.

Add the functions to add/remove elements from the hashed secret obj list.
These will replace secret_driver functions secretAssignDef and secretObjRemove.

The virSecretObjListAddLocked will perform the necessary lookups and
decide whether to replace an existing hash entry or create a new one.
This includes setting up the configPath and base64Path as well as being
able to support the caller's need to restore from a previous definition
in case something goes wrong in the caller.

New API's including unlocked and Locked versions in order to be able
to use in either manner.

Support for searching hash object lists instead of linked lists will
replace existing secret_driver functions secretFindByUUID and
secretFindByUsage

Move virSecretObj from secret_driver.c to virsecretobj.h

To support being able to create a hashed secrets list, move the
virSecretObj to virsecretobj.h so that the code can at least find
the definition.

This should be a temporary situation while the virsecretobj.c code
is patched in order to support a hashed secret object while still
having the linked list support in secret_driver.c. Eventually, the
goal is to move the virSecretObj into virsecretobj.c, although it
is notable that the existing model from which virSecretObj was
derived has virDomainObj in src/conf/domain_conf.h and virNetworkObj
in src/conf/network_conf.h, so virSecretObj wouldn't be unique if
it were to remain in virsecretobj.h  Still adding accessors to fetch
and store hashed object data will be the end goal.

Add definitions and infrastucture in virsecretobj.c to create and
handle a hashed virSecretObj and virSecretObjList including the class,
object, lock setup, and disposal API's. Nothing will call these yet.

This infrastructure will replace the forward linked list logic
within the secret_driver, eventually.