client/tailscale/apitype: move local API types to new apitype package

They were scattered/duplicated in misc places before.

It can't be in the client package itself for circular dep reasons.

This new package is basically tailcfg but for localhost
communications, instead of to control.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>

ipn/ipnlocal/local.go

@@ -25,6 +25,7 @@ import (
 	"time"
 
 	"inet.af/netaddr"
+	"tailscale.com/client/tailscale/apitype"
 	"tailscale.com/control/controlclient"
 	"tailscale.com/health"
 	"tailscale.com/internal/deepprint"
@@ -2173,7 +2174,7 @@ func (b *LocalBackend) TestOnlyPublicKeys() (machineKey tailcfg.MachineKey, node
 	return tailcfg.MachineKey(mk), tailcfg.NodeKey(nk)
 }
 
-func (b *LocalBackend) WaitingFiles() ([]WaitingFile, error) {
+func (b *LocalBackend) WaitingFiles() ([]apitype.WaitingFile, error) {
 	b.mu.Lock()
 	apiSrv := b.peerAPIServer
 	b.mu.Unlock()
@@ -2203,19 +2204,9 @@ func (b *LocalBackend) OpenFile(name string) (rc io.ReadCloser, size int64, err
 	return apiSrv.OpenFile(name)
 }
 
-// FileTarget is a node to which files can be sent, and the PeerAPI
-// URL base to do so via.
-type FileTarget struct {
-	Node *tailcfg.Node
-
-	// PeerAPI is the http://ip:port URL base of the node's peer API,
-	// without any path (not even a single slash).
-	PeerAPIURL string
-}
-
 // FileTargets lists nodes that the current node can send files to.
-func (b *LocalBackend) FileTargets() ([]*FileTarget, error) {
-	var ret []*FileTarget
+func (b *LocalBackend) FileTargets() ([]*apitype.FileTarget, error) {
+	var ret []*apitype.FileTarget
 
 	b.mu.Lock()
 	defer b.mu.Unlock()
@@ -2232,7 +2223,7 @@ func (b *LocalBackend) FileTargets() ([]*FileTarget, error) {
 			continue
 
 		}
-		ret = append(ret, &FileTarget{
+		ret = append(ret, &apitype.FileTarget{
 			Node:       p,
 			PeerAPIURL: peerAPI,
 		})