Add auth for mongoose_domain_handler

[arcusfelis]

This PR addresses #

Proposed changes include:

• auth
• tests

[codecov]

Codecov Report

Merging #3160 (f45ced8) into master (0d82dc9) will decrease coverage by 0.00%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #3160      +/-   ##
==========================================
- Coverage   79.89%   79.88%   -0.01%     
==========================================
  Files         396      396              
  Lines       32335    32356      +21     
==========================================
+ Hits        25834    25849      +15     
- Misses       6501     6507       +6     

Impacted Files	Coverage Δ
src/config/mongoose_config_spec.erl	98.52% <100.00%> (+0.03%)	⬆️
src/domain/mongoose_domain_handler.erl	98.71% <100.00%> (+0.28%)	⬆️
src/mam/mod_mam_rdbms_async_pool_writer.erl	62.96% <0.00%> (-4.63%)	⬇️
src/mongoose_tcp_listener.erl	76.59% <0.00%> (-4.26%)	⬇️
...bal_distrib/mod_global_distrib_hosts_refresher.erl	73.58% <0.00%> (-3.78%)	⬇️
src/cassandra/mongoose_cassandra_worker.erl	70.75% <0.00%> (-2.36%)	⬇️
src/ejabberd_s2s_out.erl	60.82% <0.00%> (-1.14%)	⬇️
src/muc_light/mod_muc_light_utils.erl	90.00% <0.00%> (-1.00%)	⬇️
...c/global_distrib/mod_global_distrib_server_mgr.erl	76.27% <0.00%> (-0.57%)	⬇️
src/ejabberd_c2s.erl	89.21% <0.00%> (-0.08%)	⬇️
... and 11 more

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[chrzaszcz]

The code looks good in general. I have some minor comments.

[chrzaszcz]

I am not sure if it's good to set up such defaults in the config file... they aren't more secure than having no auth. Maybe we could leave out these two options? This way the user would have to consciously set something here. This would be also more in line with the docs, which document these two fields as empty by default. I know that this is not equal to them being empty in the default config file... but in this case I think they can be.

[arcusfelis]

do we have a way to dynamically start cowboy handlers?

[chrzaszcz]

One more thing, it would be good to add a test case to config_parser_SUITE similar to listen_http_handlers_api, called e.g. listen_http_handlers_domain.

[chrzaszcz]

Looks good! I have two minor remarks.

[chrzaszcz]

Great!