feat: add generic protobuf (#2634)

* Added generic proto file with basic Value message

* Added basic Array message to represent arrays

* Added Tuple message to represent tuples

* Added timestamp and duration datatypes

* Added concise todo comments

* Changed field names, message name `NumpyNdarray`

* Applied changed message name, moved todo comment

* Added trailing newline

* Fixed sint32 and sint64 field names

Co-authored-by: Sadab Hafiz <sadabhafizny@gmail.com>

protos/io_descriptors.proto

@@ -0,0 +1,52 @@
+syntax = "proto3";
+
+import "google/protobuf/timestamp.proto";
+import "google/protobuf/duration.proto";
+
+/* Value represents a single instance of the supported datatypes. */
+// TODO: int32, int64, fixed32, fixed64, sfixed32, sfixed64
+message Value{
+	oneof dtype{
+		float float_=1;
+		double double_=2;
+		uint32 uint32_=3;
+		uint64 uint64_=4;
+		sint32 sint32_=5;
+		sint64 sint64_=6;
+		google.protobuf.Timestamp timestamp_=7;
+		google.protobuf.Duration duration_=8;
+		bool bool_=9;
+		string string_=10;
+		bytes bytes_=11;
+		Value value_=12;
+		NumpyNdarray array_=13;
+		Tuple tuple_=14;
+	}
+}
+
+/* Tuple represents a repeated field containing data with same or different datatypes */
+message Tuple{
+	repeated Value value_=1;
+}
+
+// TODO: message complex types
+
+/* NumpyNdarray contains a dtype which identifies the type of the array.
+ * The repeated field for the identified dtype contains the array. */
+// TODO: int32, int64, fixed32, fixed64, sfixed32, sfixed64
+message NumpyNdarray {
+	string dtype=1;
+	repeated float float_=2;
+	repeated double double_=3;
+	repeated uint32 uint32_=4;
+	repeated uint64 uint64_=5;
+	repeated sint32 sint32_=6;
+	repeated sint64 sint64_=7;
+	repeated google.protobuf.Timestamp timestamp_=8;
+	repeated google.protobuf.Duration duration_=9;
+	repeated bool bool_=10;
+	repeated string string_=11;
+	repeated bytes bytes_=12;
+	repeated NumpyNdarray array_=13;
+	repeated Tuple tuple_=14;
+}