optimize IPAM pool selections

[Icarus9913]

The Spiderpool IPAM has the ability to allocate IP addresses from an array of IPPools. If you use ipam.spidernet.io/ippool or ipam.spidernet.io/ippools annotation to specify IPPools or you use CNI configuration default_ipv4_ippool to specify IPPools, the system would allocate IPs from these IPPools in order.
For instance:

annotations:
  ipam.spidernet.io/ippools: |-
    {"ipv4": ["pool1","pool2","pool3"]}

But once if you do not set any annotation or CNI configuration rules, the backend system will search all SpiderIPPool resources with "Spec.Default == true". In this case, the backend system can't control the sequence for the IPPool candidates array and may lead to #2042 .

Consequently, I optimize the backend logic and sort the IPPool candidates sequence with the filter rules.
And it's suitable for all IPPool allocation rules.

For example:

If you have these IPPools:
Pool1, PodAffinity
Pool2, NodeName
Pool3, NamespaceName
Pool4, MultusName
Pool5

And you will get the IPPool candidates just like: ["pool1", "pool3", "pool2", "pool4", "pool5"]

or

If you have these IPPools:
Pool1, PodAffinity
Pool2, NodeName
Pool3, NodeName && NamespaceName
Pool4, NamespaceName && MultusName

And you will get the IPPool candidates just like: ["pool1", "pool3", "pool2", "pool4"]

Signed-off-by: Icarus9913 [email protected]

What this PR does / why we need it:
new feature

Which issue(s) this PR fixes:
close #2042

[codecov]

Codecov Report

Merging #2207 (c17f374) into main (aa2d201) will increase coverage by 0.14%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main    #2207      +/-   ##
==========================================
+ Coverage   80.99%   81.14%   +0.14%     
==========================================
  Files          49       49              
  Lines        5236     5277      +41     
==========================================
+ Hits         4241     4282      +41     
  Misses        832      832              
  Partials      163      163              

Flag	Coverage Δ
unittests	81.14% <100.00%> (+0.14%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files Changed	Coverage Δ
pkg/ippoolmanager/utils.go	92.77% <100.00%> (+7.05%)	⬆️