Integrate with 10up Safe SVG

[benlk]

Is your enhancement related to a problem? Please describe.

Following from @meksone's request in #810 (comment) , it seems like we should integrate these two 10up-maintained plugins.

See parallel issue 10up/safe-svg#225

Minimum criteria for this task:

• Safe SVG: Add support on the sending and receiving Distributor site via the dt_allowed_media_extensions filter
• Distributor: Test that, if Safe SVG is enabled, then an attached SVG is distributed
• Distributor: Test that, if Safe SVG is enabled, then a distributed SVG is received and imported
• Safe SVG: Test that when importing via Distributor, imported SVGs are run through Safe SVG's usual processes for clearing SVGs

Designs

No response

Describe alternatives you've considered

No response

Code of Conduct

• I agree to follow this project's Code of Conduct