feat(image): add image upload support

[NeverBehave]

Fixes: #520

This PR adds automatic file upload support for endpoints that accept files (e.g., image attachments, device type images).

Changes:

• Auto-detect file-like objects in create()/save() data and switch from JSON to multipart/form-data encoding
• Support for single and multiple file uploads in one request
• Added helper functions _is_file_like() and _extract_files() in query.py

[jeremystretch]

@NeverBehave please don't request reviews from individuals unless someone has previously volunteered. We utilize a rotation for assignment of reviewers.

[NeverBehave]

@jeremystretch The request is sent automatically(and won't be able to deselect) by Github since this repo has defined CODEOWNERS, which was added 7 month ago by @arthanson

Reference: https://docs.github.com/en/repositories/managing-your-repositorys-settings-and-features/customizing-your-repository/about-code-owners#about-code-owners

[jeremystretch]

My mistake, thanks for pointing that out. Not sure why that was added as it's not needed. I've opened #717 to remove it.

[arthanson]

@NeverBehave this looks very good, just a couple questions below.

[NeverBehave]

@arthanson thanks for the review. Both cases updated with corresponded tests covered.

Let me know if there is any other concerns.

[arthanson]

@NeverBehave some of the tests are failing, can you please check

[jnovinger]

@NeverBehave, in the future, please comment on the original issue asking that it be assigned to you. We do not accept PRs for unassigned issues. Since this has already received a review, please comment on #520 now so that I can assign to you.

[NeverBehave]

@jnovinger I leave a comment on the original issue. Let me know anything else needed.

It would be great if this process("ask for assignment") documented in https://github.com/netbox-community/pynetbox/blob/c70d57b455ece7fb5fa6e291a1c6901a60b88054/docs/development/index.md?plain=1

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Some other quick housekeeping thoughts:

1. Make use of CONTRIBUTING.md https://docs.github.com/en/communities/setting-up-your-project-for-healthy-contributions/setting-guidelines-for-repository-contributors
2. getting started guide is missing info around blank lint used in Github Action: https://github.com/netbox-community/pynetbox/blob/c70d57b455ece7fb5fa6e291a1c6901a60b88054/docs/development/getting-started.md

[arthanson]

Thanks @NeverBehave !

[NeverBehave]

Quick question — what’s the usual release cadence for this project?