Add v2 version to go module name

Replace all elements from `v2` to root directory.

Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>

netmap/json.go

@@ -0,0 +1,62 @@
+package netmap
+
+import (
+	netmap "github.com/nspcc-dev/neofs-api-go/v2/netmap/grpc"
+	"github.com/nspcc-dev/neofs-api-go/v2/rpc/message"
+)
+
+func (p *PlacementPolicy) MarshalJSON() ([]byte, error) {
+	return message.MarshalJSON(p)
+}
+
+func (p *PlacementPolicy) UnmarshalJSON(data []byte) error {
+	return message.UnmarshalJSON(p, data, new(netmap.PlacementPolicy))
+}
+
+func (f *Filter) MarshalJSON() ([]byte, error) {
+	return message.MarshalJSON(f)
+}
+
+func (f *Filter) UnmarshalJSON(data []byte) error {
+	return message.UnmarshalJSON(f, data, new(netmap.Filter))
+}
+
+func (s *Selector) MarshalJSON() ([]byte, error) {
+	return message.MarshalJSON(s)
+}
+
+func (s *Selector) UnmarshalJSON(data []byte) error {
+	return message.UnmarshalJSON(s, data, new(netmap.Selector))
+}
+
+func (r *Replica) MarshalJSON() ([]byte, error) {
+	return message.MarshalJSON(r)
+}
+
+func (r *Replica) UnmarshalJSON(data []byte) error {
+	return message.UnmarshalJSON(r, data, new(netmap.Replica))
+}
+
+func (a *Attribute) MarshalJSON() ([]byte, error) {
+	return message.MarshalJSON(a)
+}
+
+func (a *Attribute) UnmarshalJSON(data []byte) error {
+	return message.UnmarshalJSON(a, data, new(netmap.NodeInfo_Attribute))
+}
+
+func (ni *NodeInfo) MarshalJSON() ([]byte, error) {
+	return message.MarshalJSON(ni)
+}
+
+func (ni *NodeInfo) UnmarshalJSON(data []byte) error {
+	return message.UnmarshalJSON(ni, data, new(netmap.NodeInfo))
+}
+
+func (i *NetworkInfo) MarshalJSON() ([]byte, error) {
+	return message.MarshalJSON(i)
+}
+
+func (i *NetworkInfo) UnmarshalJSON(data []byte) error {
+	return message.UnmarshalJSON(i, data, new(netmap.NetworkInfo))
+}