feature/did accounts (#23)

* feat: add support for DID number as primary key for Controllers

* refactor: rename pkg/proxy to app/proxy

* feat: add vault module keeper tests

* feat(vault): add DID keeper to vault module

* refactor: move vault client code to its own package

* refactor(vault): extract schema definition

* refactor: use vaulttypes for MsgAllocateVault

* refactor: update vault assembly logic to use new methods

* feat: add dwn-proxy command

* refactor: remove unused context.go file

* refactor: remove unused web-related code

* feat: add DWN proxy server

* feat: add BuildTx RPC to vault module

* fix: Implement BuildTx endpoint

* feat: add devbox integration to project

x/vault/client/dwn/middleware/token.go

@@ -0,0 +1,51 @@
+package middleware
+
+import (
+	"fmt"
+	"time"
+)
+
+const (
+	OriginMacroonCaveat  MacroonCaveat = "origin"
+	ScopesMacroonCaveat  MacroonCaveat = "scopes"
+	SubjectMacroonCaveat MacroonCaveat = "subject"
+	ExpMacroonCaveat     MacroonCaveat = "exp"
+	TokenMacroonCaveat   MacroonCaveat = "token"
+)
+
+type MacroonCaveat string
+
+func (c MacroonCaveat) Equal(other string) bool {
+	return string(c) == other
+}
+
+func (c MacroonCaveat) String() string {
+	return string(c)
+}
+
+func (c MacroonCaveat) Verify(value string) error {
+	switch c {
+	case OriginMacroonCaveat:
+		return nil
+	case ScopesMacroonCaveat:
+		return nil
+	case SubjectMacroonCaveat:
+		return nil
+	case ExpMacroonCaveat:
+		// Check if the expiration time is still valid
+		exp, err := time.Parse(time.RFC3339, value)
+		if err != nil {
+			return err
+		}
+		if time.Now().After(exp) {
+			return fmt.Errorf("expired")
+		}
+		return nil
+	case TokenMacroonCaveat:
+		return nil
+	default:
+		return fmt.Errorf("unknown caveat: %s", c)
+	}
+}
+
+var MacroonCaveats = []MacroonCaveat{OriginMacroonCaveat, ScopesMacroonCaveat, SubjectMacroonCaveat, ExpMacroonCaveat, TokenMacroonCaveat}