Provide helpers to combine few callbacks for body-/meta-filters

[nolar]

What do these changes do?

Little helpers to combined few callbacks for when= or labels/annotations filters.

Description

Nothing more that a little bit of syntax sugar with kopf.all_() and kopf.any_():

import kopf

def whole_fn1(name, **_): return name.startswith('kopf-')
def whole_fn2(spec, **_): return spec.get('field') == 'value'
def value_fn1(value, **_): return value.startswith('some')
def value_fn2(value, **_): return value.endswith('label')

@kopf.on.create('zalando.org', 'v1', 'kopfexamples',
                when=kopf.all_([whole_fn1, whole_fn2]),
                labels={'somelabel': kopf.all_([value_fn1, value_fn2])})
def create_fn1(**_):
    pass

@kopf.on.create('zalando.org', 'v1', 'kopfexamples',
                when=kopf.any_([whole_fn1, whole_fn2]),
                labels={'somelabel': kopf.any_([value_fn1, value_fn2])})
def create_fn2(**_):
    pass

Based on the experience when few arbitrary criteria should be combined onto one criterion, but it looks ugly to add too many one-liner single-use functions that call real meaningful functions with and/or operators.

Issues/PRs

Issues: #123 #98

Type of changes

• New feature (non-breaking change which adds functionality)

Checklist

• The code addresses only the mentioned problem, and this problem only
• I think the code is well written
• Unit tests for the changes exist
• Documentation reflects the changes
• If you provide code modification, please add yourself to CONTRIBUTORS.txt

[zincr]

🤖 zincr found 0 problems , 1 warning

ℹ️ Large Commits
✅ Approvals
✅ Specification
✅ Dependency Licensing

Details on how to resolve are provided below

---

Large Commits

Checks all commits for large additions to a single file. Large commits should be reviewed more carefully for potential copyright and licensing issues

This file contains a substantial change, please review to determine if the change comes from an external source and if there are any copyright or licensing issues to be aware of

• ℹ️ tests/test_filtering_helpers.py had +100 lines of code changed in a single commit
  Please review this file to determine the source of this change
   

[zincr]

🤖 zincr found 1 problem , 0 warnings

❌ Approvals
✅ Large Commits
✅ Specification
✅ Dependency Licensing

Details on how to resolve are provided below

---

Approvals

All proposed changes must be reviewed by project maintainers before they can be merged

Not enough people have approved this pull request - please ensure that 1 additional user, who have not contributed to this pull request approve the changes.

• ✅ Approved by PR author @nolar
• ❌ 1 additional approval needed