[Confluence] Update template methods as they are no longer experimental

[dephekt]

Confluence template API transitioned to a stable version. Some things in our module are no longer in line with reality. The endpoint URL has changed to wiki/rest/api/template and some parameters have changed behavior. When getting templates or blueprints, a space is not required. If it's not given, all templates in the scope will be returned. I updated the parameters to not be required. The limit has also been updated to a default of 25. I switched those limit parameters to have a default "None" type, so if they're not specified, we don't pass them and we'll get the default API behavior.

We don't currently support deleting templates or creating/updating new content templates but there are REST API methods for that, so now is a good time to write that support.

Fixes #715

[dephekt]

Drafting this until I finish writing the support for the three extra methods we don't support yet: create, update, and delete.

Edit: That's done, moving this to ready for review.

[dephekt]

This needs tested before merging. I don't use or have Confluence in my org so if someone could test the new methods and confirm the old methods that I touched here are working that would be awesome 🎉

I left instructions here on what exactly needs checked: #715 (comment)

[dephekt]

I also want to refactor the method names to be in-line with the upstream API methods, see this comment since I posted it in the issue instead of here by accident: #715 (comment)

[dephekt]

This is ready to be merged as soon as someone is able to test the template methods.

[dephekt]

Just rebasing off the current master. This is still ready to merge.

[codecov-io]

Codecov Report

Merging #731 (e628308) into master (f9ba354) will decrease coverage by 0.04%.
The diff coverage is 28.57%.

@@            Coverage Diff             @@
##           master     #731      +/-   ##
==========================================
- Coverage   36.71%   36.67%   -0.05%     
==========================================
  Files          32       32              
  Lines        5556     5571      +15     
  Branches      794      798       +4     
==========================================
+ Hits         2040     2043       +3     
- Misses       3433     3445      +12     
  Partials       83       83              

Impacted Files	Coverage Δ
atlassian/confluence.py	12.82% <28.57%> (+0.10%)	⬆️

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[dephekt]

Need to readd old method names and add depreciation notice.

[gonchik]

@dephekt Thank you! 👍🏽