ipcache: Refactor CIDR identity allocation to accept labels from caller
ipcache: Refactor CIDR identity allocation to accept labels from caller

This commit refactors the function for allocating CIDR identities for
prefixes to accept labels from the caller, as well as making it generic
for any identity allocation (not exclusive to CIDR). The lower-level
function now operates on a single prefix and its associated labels,
while the higher-level functions perform the iteration over a slice of
prefixes, passing in the default CIDR labels for each prefix.

Now that the lower-level function is no longer specific to allocating
CIDR identities, rename it to reflect its generic nature. The CIDR label
is only attached to the identity if the prefix is associated with world.

This refactor is useful in subsequent commits where the caller of the
lower-level function will want to control the labels associated with a
prefix.

Signed-off-by: Chris Tarazi <711c73f64afdce07b7e38039a96d2224209e9a6c@isovalent.com>
Signed-off-by: Joe Stringer <16a9a54ddf4259952e3c118c763138e83693d7fd@cilium.io>

cilium/cilium,michi-covalent/cilium,michi-covalent/cilium,cilium/cilium,michi-covalent/cilium,cilium/cilium,cilium/cilium,michi-covalent/cilium,cilium/cilium,michi-covalent/cilium