Allow a default rescale parameter to be set via a dependency

[samn]

What I am changing

• Add a rescale_dependency field to BaseTilerFactory & MosaicTilerFactory (defaulting to the existing RescalingParams) so users can override the logic for supplying the rescale value. This lets us define a default rescale value from a separate config without needing to include it in the query params for every request.

How I did it

• Added a dependency to get the rescale value, rather than using a Query directly that can't be overridden.

How you can test it

• Via the integration tests, or by using the rescale_dependency in an existing application.

[vincentsarago]

🙏 nice addition @samn

would you be able to add something in the changelog (under a ##Next item) 🙏

[samn]

Thanks @vincentsarago! Just pushed an update to CHANGES.md

[vincentsarago]

thank you @samn 🙏