[#1608] qos: Add client grpc interceptors

`qos` client interceptors replace internal IO tags `writecache`,
`policer` and `background` with `internal` IO tag for outcomming RPC.

Signed-off-by: Dmitrii Stepanov <d.stepanov@yadro.com>

internal/qos/grpc.go

@@ -0,0 +1,51 @@
+package qos
+
+import (
+	"context"
+
+	"git.frostfs.info/TrueCloudLab/frostfs-qos/tagging"
+	"google.golang.org/grpc"
+)
+
+func NewSetCriticalIOTagUnaryServerInterceptor() grpc.UnaryServerInterceptor {
+	return func(ctx context.Context, req any, _ *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (resp any, err error) {
+		ctx = tagging.ContextWithIOTag(ctx, IOTagCritical.String())
+		return handler(ctx, req)
+	}
+}
+
+func NewAdjustOutgoingIOTagUnaryClientInterceptor() grpc.UnaryClientInterceptor {
+	return func(ctx context.Context, method string, req, reply any, cc *grpc.ClientConn, invoker grpc.UnaryInvoker, opts ...grpc.CallOption) error {
+		rawTag, ok := tagging.IOTagFromContext(ctx)
+		if !ok {
+			return invoker(ctx, method, req, reply, cc, opts...)
+		}
+		tag, err := FromRawString(rawTag)
+		if err != nil {
+			tag = IOTagClient
+		}
+		if tag == IOTagBackground || tag == IOTagPolicer || tag == IOTagWritecache {
+			tag = IOTagInternal
+		}
+		ctx = tagging.ContextWithIOTag(ctx, tag.String())
+		return invoker(ctx, method, req, reply, cc, opts...)
+	}
+}
+
+func NewAdjustOutgoingIOTagStreamClientInterceptor() grpc.StreamClientInterceptor {
+	return func(ctx context.Context, desc *grpc.StreamDesc, cc *grpc.ClientConn, method string, streamer grpc.Streamer, opts ...grpc.CallOption) (grpc.ClientStream, error) {
+		rawTag, ok := tagging.IOTagFromContext(ctx)
+		if !ok {
+			return streamer(ctx, desc, cc, method, opts...)
+		}
+		tag, err := FromRawString(rawTag)
+		if err != nil {
+			tag = IOTagClient
+		}
+		if tag == IOTagBackground || tag == IOTagPolicer || tag == IOTagWritecache {
+			tag = IOTagInternal
+		}
+		ctx = tagging.ContextWithIOTag(ctx, tag.String())
+		return streamer(ctx, desc, cc, method, opts...)
+	}
+}