multi: add new build tag integration

This commit adds a new build tag `integration` and removes the old tag
`rpctest` for clarity. Multiple unnecessary usages of `build !rpctest`
is also removed.

macaroons/security_integration.go

@@ -0,0 +1,14 @@
+//go:build integration
+
+package macaroons
+
+import "github.com/btcsuite/btcwallet/waddrmgr"
+
+func init() {
+	// Below are the reduced scrypt parameters that are used when creating
+	// the encryption key for the macaroon database with snacl.NewSecretKey.
+	// We use very low values for our itest/rpctest to speed things up.
+	scryptN = waddrmgr.FastScryptOptions.N
+	scryptR = waddrmgr.FastScryptOptions.R
+	scryptP = waddrmgr.FastScryptOptions.P
+}