Add catalogsConfigmapOverride

[soft-titus]

This to provide ability to use our own configmap for the catalogs instead of adding the catalogs inline in the values.yaml, for example :

catalogsConfigmapOverride: my-trino-catalog-configmap

Thanks.

[cla-bot]

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[nineinchnick]

@soft-titus can you rebase, and configure it in https://github.com/trinodb/charts/blob/main/test-values.yaml, so we can see if it works?