Change AddressValidationRules API

[Kwaidan00]

I want to merge this change because it brings several minor changes to the AddressValidationRules endpoint.
First of all, it changes query's signature to take country code of type CountryCode!, adds city to the parameters, it drops support for country guessing based on GeoIP.
The second thing is returning allowed and required field names in camel case to be consistent with AddressInput field names.

It fixes #4514 and it fixes #4541.

Pull Request Checklist

1. Privileged views and APIs are guarded by proper permission checks.
2. All visible strings are translated with proper context.
3. All data-formatting is locale-aware (dates, numbers, and so on).
4. Database queries are optimized and the number of queries is constant.
5. Database migration files are up to date.
6. The changes are tested.
7. GraphQL schema and type definitions are up to date.
8. Changes are mentioned in the changelog.

[django-queries]

Here is the report for f33fb0a (mirumee/saleor @ change-address-validator-api)
Base comparison is de8091e.

No differences were found. (click me)

# api.benchmark checkout
  test name                           	left count 	right count	duplicate count
  ------------------------------------	-----------	-----------	---------------
  add billing address to checkout     	         34	         34	             20
  add shipping to checkout            	          7	          7	              0
  checkout payment charge             	         14	         14	              0
  complete checkout                   	          6	          6	              0
  create checkout                     	         48	         48	             24

# api.benchmark homepage
  test name                           	left count 	right count	duplicate count
  ------------------------------------	-----------	-----------	---------------
  retrieve main menu                  	          5	          5	              0
  retrieve product list               	          4	          4	              0
  retrieve secondary menu             	          5	          5	              0
  retrieve shop                       	          2	          2	              0

# api.benchmark product
  test name                           	left count 	right count	duplicate count
  ------------------------------------	-----------	-----------	---------------
  product details                     	         13	         13	              3

# api.benchmark variant
  test name                           	left count 	right count	duplicate count
  ------------------------------------	-----------	-----------	---------------
  retrieve variant list               	         15	         15	              8

[codecov]

Codecov Report

Merging #4655 into master will increase coverage by <.01%.
The diff coverage is 94.44%.

@@            Coverage Diff             @@
##           master    #4655      +/-   ##
==========================================
+ Coverage   91.36%   91.37%   +<.01%     
==========================================
  Files         308      308              
  Lines       18236    18244       +8     
  Branches     1814     1816       +2     
==========================================
+ Hits        16662    16671       +9     
+ Misses       1059     1058       -1     
  Partials      515      515

Impacted Files	Coverage Δ
saleor/graphql/account/resolvers.py	100% <100%> (+5%)	⬆️
saleor/graphql/account/schema.py	100% <100%> (ø)	⬆️
saleor/graphql/account/utils.py	97.56% <92.3%> (-2.44%)	⬇️

---

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[codecov]

Codecov Report

Merging #4655 into master will decrease coverage by 0.05%.
The diff coverage is 94.44%.

@@            Coverage Diff             @@
##           master    #4655      +/-   ##
==========================================
- Coverage   91.43%   91.37%   -0.06%     
==========================================
  Files         307      308       +1     
  Lines       18419    18244     -175     
  Branches     1842     1816      -26     
==========================================
- Hits        16841    16671     -170     
+ Misses       1060     1058       -2     
+ Partials      518      515       -3

Impacted Files	Coverage Δ
saleor/graphql/account/resolvers.py	100% <100%> (+5%)	⬆️
saleor/graphql/account/schema.py	100% <100%> (ø)	⬆️
saleor/graphql/account/utils.py	97.56% <92.3%> (-2.44%)	⬇️
saleor/discount/utils.py	96.84% <0%> (-3.16%)	⬇️
saleor/graphql/product/filters.py	91.27% <0%> (-1.04%)	⬇️
saleor/graphql/product/resolvers.py	84.84% <0%> (-0.45%)	⬇️
saleor/graphql/product/enums.py	92.59% <0%> (-0.27%)	⬇️
saleor/graphql/account/mutations/base.py	98.12% <0%> (-0.24%)	⬇️
saleor/product/models.py	94.38% <0%> (-0.17%)	⬇️
saleor/payment/models.py	94.89% <0%> (-0.11%)	⬇️
... and 29 more

---

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Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 8b75634...f33fb0a. Read the comment docs.