feature/1109 grpc session model (#1141)

- **feat: remove Hway deployment**
- **feat: introduce session middleware for requests**
- **refactor: update path imports to use new pkg folder**
- **feat: add gRPC client for interacting with services**
- **feat: remove grpc client and use REST api**
- **refactor: move  from  to**
- **feat: add client views endpoint**
- **feat: add webauthn support**
- **closes: #1124**
- **refactor: Improve PR labeler configuration**
- **feat: add milestone discussion template**
- **feat: remove OKR tracking issue template**
- **feat: use gorilla sessions for session management**
- **refactor: move pubkey related code to**
- **<no value>**
- **refactor: remove unused identifier type**
- **feat: integrate Macaroon Keeper with Service Module**
- **refactor: rename worker routes for clarity**

internal/ctx/store.go

@@ -0,0 +1,142 @@
+package ctx
+
+import (
+	"fmt"
+
+	"github.com/go-webauthn/webauthn/protocol"
+	"github.com/gorilla/sessions"
+	"github.com/labstack/echo/v4"
+)
+
+type WebBytes = protocol.URLEncodedBase64
+
+type Session interface {
+	ID() string
+	Origin() string
+
+	Address() string
+	ChainID() string
+
+	GetChallenge(subject string) (WebBytes, error)
+	ValidateChallenge(challenge WebBytes, subject string) error
+
+	IsState(State) bool
+	SaveHTTP(c echo.Context) error
+}
+
+func defaultSession(id string, s *sessions.Session) *session {
+	return &session{
+		session: s,
+		id:      id,
+		origin:  "",
+		address: "",
+		chainID: "",
+		state:   StateUnauthenticated,
+	}
+}
+
+func NewSessionFromValues(vals map[interface{}]interface{}) *session {
+	s := &session{
+		id:        vals["id"].(string),
+		origin:    vals["origin"].(string),
+		address:   vals["address"].(string),
+		chainID:   vals["chainID"].(string),
+		state:     StateFromString(vals["state"].(string)),
+		challenge: vals["challenge"].(WebBytes),
+		subject:   vals["subject"].(string),
+	}
+	return s
+}
+
+type session struct {
+	// Defaults
+	session *sessions.Session
+	id      string // Generated ksuid http cookie; Initialized on first request
+	origin  string // Webauthn mapping to Relaying Party ID; Initialized on first request
+
+	// Initialization
+	address string // Webauthn mapping to User ID; Supplied by DWN frontend
+	chainID string // Macaroon mapping to location; Supplied by DWN frontend
+
+	// Authentication
+	challenge WebBytes // Webauthn mapping to Challenge; Per session based on origin
+	subject   string   // Webauthn mapping to User Displayable Name; Supplied by DWN frontend
+
+	// State
+	state State
+}
+
+func (s *session) ID() string {
+	return s.id
+}
+
+func (s *session) Origin() string {
+	return s.origin
+}
+
+func (s *session) Address() string {
+	return s.address
+}
+
+func (s *session) ChainID() string {
+	return s.chainID
+}
+
+func (s *session) GetChallenge(subject string) (WebBytes, error) {
+	if s.challenge == nil {
+		return nil, nil
+	}
+	return s.challenge, nil
+}
+
+func (s *session) ValidateChallenge(challenge WebBytes, subject string) error {
+	if s.challenge == nil {
+		return nil
+	}
+	if s.challenge.String() != challenge.String() {
+		return fmt.Errorf("invalid challenge")
+	}
+	s.subject = subject
+	s.state = StateAuthenticated
+	return nil
+}
+
+func (s *session) IsState(state State) bool {
+	return s.state == state
+}
+
+func (s *session) SaveHTTP(c echo.Context) error {
+	sess, err := store.Get(c.Request(), s.id)
+	if err != nil {
+		return err
+	}
+	sess.Values = s.Values()
+	err = sess.Save(c.Request(), c.Response().Writer)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func (s *session) Values() map[interface{}]interface{} {
+	vals := make(map[interface{}]interface{})
+	vals["id"] = s.id
+	vals["address"] = s.address
+	vals["chainID"] = s.chainID
+	vals["state"] = s.state
+	vals["challenge"] = s.challenge
+	vals["subject"] = s.subject
+	return vals
+}
+
+func GetSession(c echo.Context) Session {
+	id, _ := getSessionID(c.Request().Context())
+	sess, _ := store.Get(c.Request(), id)
+	if sess.IsNew {
+		s := defaultSession(id, sess)
+		s.SaveHTTP(c)
+		return s
+	}
+	s, _ := readSessionFromStore(c, id)
+	return s
+}