fix: ModelReference deployment for Alt Configs models

[malav-shastri]

Issue #, if available:
(Please check the internal ticket for the latest updates)

Description of changes:
We have identified that currently Model Ref deployment in CuratedHub is broken which looks like in general incompatibility of new QS code with CuratedHub Code path + some Schema parsing issues.

• Parser issue: where is_hub_content flag is not set for the alt config parsing, resulting in failure when parsing the Alt config schema

• Parser issue: inference_configs_dict is not being fetched correctly from the json object which results in AttributeError: 'JumpStartScriptScope' object has no attribute 'get'

• hub_arn has not been passed for get_jumpstart_configs() resulting in empty hub_arn and code path for curatedHub is not getting executed.

• when get_top_config_from_ranking() returns None there's no handling of None response in the _add_config_name_to_init_kwargs() function which results in key error.

Testing done:

• Notebook testing, tried to deploy the ModelReference using the local changes

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[Captainia]

I'm not sure if this works, now that the inference_configs_dict becomes a json object, how would we construct the JumpStartMetadataConfig class without parsing the json?

[bencrabtree]

+1, also curious if we should do .get here also to mitigate future errors

[JGuinegagne]

if we reintroduce the code above, please create a dedicated utility & unit test separately.

dict comprehension coupled w/ ternary operator are cool, but they make the code much harder to read and maintain.

[Captainia]

non-blocking: since we are here, it would be good if we could update line 1792 for training configs, but doesn't have to be in this PR.

[malav-shastri]

thanks for the callout, I added those changed as well

[Captainia]

Please add unittest coverage that in types.py, we should catch issues like this in the future

[malav-shastri]

Please add unittest coverage that in types.py, we should catch issues like this in the future

sure I'll have a followup PR for that right after this one, I believe we should be unblocking the customers here first

[nileshvd]

I dont have context about this change. But since Captainia@ has already approved the change, and since this is for an active sev2 I am approving this change.