Add ability to assign multiple warehouses in mutations to create/update a shipping zone

[fowczarek]

I want to merge this change because adding the ability to assign multiple warehouses in mutations to create/update a shipping zone.

In shippingZoneCreate mutation I add the field with warehouses to add to a shipping zone.
In shippingZoneUpdate mutation I add fields with warehouses to add and remove from a shipping zone.

Impact

• New migrations
• New/Updated API fields or mutations
• Deprecated API fields or mutations
• Removed API types, fields, or mutations

Pull Request Checklist

• Privileged queries and mutations are guarded by proper permission checks
• Database queries are optimized and the number of queries is constant
• Database migration files are up to date
• The changes are tested
• GraphQL schema and type definitions are up to date
• Changes are mentioned in the changelog

[codecov]

Codecov Report

Merging #5399 into master will increase coverage by 0.01%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #5399      +/-   ##
==========================================
+ Coverage   91.12%   91.13%   +0.01%     
==========================================
  Files         283      283              
  Lines       18297    18324      +27     
  Branches     1601     1607       +6     
==========================================
+ Hits        16673    16700      +27     
  Misses       1195     1195              
  Partials      429      429              

Impacted Files	Coverage Δ
saleor/graphql/core/types/common.py	100.00% <100.00%> (ø)
saleor/graphql/core/utils/__init__.py	100.00% <100.00%> (ø)
saleor/graphql/shipping/mutations.py	97.53% <100.00%> (+0.42%)	⬆️
saleor/graphql/shipping/types.py	100.00% <100.00%> (ø)
saleor/shipping/error_codes.py	100.00% <100.00%> (ø)

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 880e053...52c5bb6. Read the comment docs.