Add first and last name to customer and staff module

[bonifacy1]

Todo:

• - Add first and last name to staff module
• - Add First and last name to customers module

Issue:
close #3181

[codecov]

Codecov Report

Merging #3247 into master will decrease coverage by 0.28%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #3247      +/-   ##
==========================================
- Coverage    89.7%   89.42%   -0.29%     
==========================================
  Files         237      222      -15     
  Lines       12901    12411     -490     
  Branches     1301     1234      -67     
==========================================
- Hits        11573    11098     -475     
+ Misses        922      920       -2     
+ Partials      406      393      -13

Impacted Files	Coverage Δ
saleor/core/templatetags/attributes.py	77.77% <0%> (-22.23%)	⬇️
saleor/dashboard/taxes/views.py	83.01% <0%> (-16.99%)	⬇️
saleor/graphql/core/types/money.py	91.48% <0%> (-8.52%)	⬇️
saleor/payment/gateways/dummy/__init__.py	95.91% <0%> (-4.09%)	⬇️
saleor/payment/utils.py	95.45% <0%> (-2.28%)	⬇️
saleor/search/documents.py	75% <0%> (-2.2%)	⬇️
saleor/graphql/api.py	98.13% <0%> (-1.87%)	⬇️
saleor/account/utils.py	63.63% <0%> (-1.59%)	⬇️
saleor/account/views.py	79.12% <0%> (-1.5%)	⬇️
saleor/account/forms.py	83.56% <0%> (-1.06%)	⬇️
... and 58 more

---

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[codecov]

Codecov Report

Merging #3247 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #3247   +/-   ##
=======================================
  Coverage   89.75%   89.75%           
=======================================
  Files         237      237           
  Lines       12943    12943           
  Branches     1312     1312           
=======================================
  Hits        11617    11617           
  Misses        922      922           
  Partials      404      404

---

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Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update bf652d7...8b909a2. Read the comment docs.