[OF-1805] feat: Add new GoogleGenAI Quota tier feature

[MAG-AdamThorn]

Services-level support is being added for Gemini-based services. To ensure usage is managed appropriately, we are also tracking and limiting usage via the quota system. This requires a new Quota Feature Tier type: GoogleGenAI which has been added.

Please note:
MCS have not yet added the type, which means that one of our tests GetTierFeaturesQuota, has had to be temporarily updated to account for this. Currently the GetTierFeaturesQuota returns 9 tiers, but will return 10 once MCS have added the type. Once MCS have done this I will remove the temporary workaround.

Another change I have made to the test is to no-longer validate every property of the returned FeatureQuotaInfo object as its data is subject to change at any point. This is a permanent change and will not be reverted once the new type is added by MCS.

[github-actions]

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[MAG-ChristopherAtkinson]

[Question]do we have a time line for when the GoogleGenAI with be introduces on the backend?

[MAG-AdamThorn]

[Question]do we have a time line for when the GoogleGenAI with be introduces on the backend?

The plan is to inform CHS as soon as this is merged so that they can add it in.