Add the new deprecated wagtail module routes

[Tobi-De]

This is an updated version of #28 with fixed linting issues

Thank you for contributing to Salesman, before you continue make sure that:

• Tests still pass: poetry run pytest
• There are no lint errors: poetry run pre-commit run --all-files

[codecov]

Codecov Report

Merging #33 (4057c5a) into master (2e7d7e2) will decrease coverage by 0.11%.
The diff coverage is 77.77%.

@@            Coverage Diff             @@
##           master      #33      +/-   ##
==========================================
- Coverage   99.94%   99.84%   -0.11%     
==========================================
  Files          50       50              
  Lines        1978     1984       +6     
==========================================
+ Hits         1977     1981       +4     
- Misses          1        3       +2     

Impacted Files	Coverage Δ
salesman/admin/wagtail/mixins.py	97.72% <75.00%> (-2.28%)	⬇️
salesman/admin/wagtail_hooks.py	97.95% <75.00%> (-2.05%)	⬇️
salesman/admin/wagtail/panels.py	99.12% <100.00%> (ø)

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[Tobi-De]

Hello @dinoperovic, could you please review and merge this pull request? Thank you.
I also have a question posted at #32

[dinoperovic]

@Tobi-De thanks! I will take a closer look soon.

[dinoperovic]

Hey @Tobi-De,

a new Salesman version 1.2.0 was released that drops support for older versions of Wagtail, which makes this PR obsolete.

Thank you for your effort 👍🏻