Fix: allow operational metadata to be disabled on MV's and update docs

[rederik76]

Updated docs for operational metadata and added fix to properly handling the disabling of operational metadata for MV's by either of the following methods:

Disabling the feature at Spec Level:
{
"dataFlowId": "feature_materialized_views",
"dataFlowGroup": "feature_samples",
"dataFlowType": "materialized_view",
"features": {
"operationalMetadataEnabled": false
}
}

Disable at MV level using the configFlags setting:
"targetDetails": {
"table": "customer_address",
"tableProperties": {
"delta.autoOptimize.optimizeWrite": "true",
"delta.autoOptimize.autoCompact": "true"
},
"partitionColumns": ["country_code"],
"schemaPath": "schemas/customer_address.json",
"configFlags": ["disableOperationalMetadata"]
},

[haillew]

just to make it super clear would it be better to update this to "You can disable operational metadata at a dataflow spec level or for specific target tables" or something like that to make it clear it's two different scopes not two separate items