[Feat]: Support Passing Guzzle Client Options

[NHZEX]

Feature Request Is New

• I have verified that the requested feature does not already exist or has not already been requested.

Description of the feature

Allow passing options for instantiating Guzzle during runtime, enabling lower-level request configurations such as setting network proxies.

[Justintime50]

Thanks for submitting this @NHZEX! We are looking into the ability to setup network proxies across all our libs holistically. Did you have other "lower-level" config that you wanted us to consider aside from proxies?

[NHZEX]

We can provide a handler option to add middleware, such as enabling the ability to retry network failures with caseyamcl/guzzle_retry_middleware.

Perhaps you could consider allowing support for an externally provided Client instance, so that any options can be customized. This could possibly be part of issue #318.

Please consider opening up more options while also evaluating any potential side effects on the current library itself.

[Justintime50]

Shelving for now due to prioritization. If this feature is needed, we'd consider a PR. Alternatively, the library can be forked and built for your own needs.