Extract the string representation from a proto TypedValue.
The TypedValue oneof has 8 variants (integerValue, numberValue,
stringValue, boolValue, timeValue, durationValue, urlValue, jsonValue).
Each is converted to its canonical string form.
Parameters
tv: TypedValue|undefined
Returns string
The string representation, or empty string for null/empty values.
Extract the string representation from a proto TypedValue.
The TypedValue oneof has 8 variants (integerValue, numberValue, stringValue, boolValue, timeValue, durationValue, urlValue, jsonValue). Each is converted to its canonical string form.