Expose public/ API as submodule (#23345)

* model -> public/model

* plugin -> public/plugin

* public/model/utils -> public/utils

* platform/shared/mlog -> public/shared/mlog

* platform/shared/i18n -> public/shared/i18n

* platform/shared/markdown -> public/shared/markdown

* platform/services/timezones -> public/shared/timezones

* channels/einterfaces -> einterfaces

* expose public/ submodule

* go mod tidy

* .github: cache-dependency-path, setup-go-work

* modules-tidy for public/ too

* remove old gomodtidy

server/public/model/user_access_token.go

@@ -0,0 +1,41 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package model
+
+import (
+	"net/http"
+)
+
+type UserAccessToken struct {
+	Id          string `json:"id"`
+	Token       string `json:"token,omitempty"`
+	UserId      string `json:"user_id"`
+	Description string `json:"description"`
+	IsActive    bool   `json:"is_active"`
+}
+
+func (t *UserAccessToken) IsValid() *AppError {
+	if !IsValidId(t.Id) {
+		return NewAppError("UserAccessToken.IsValid", "model.user_access_token.is_valid.id.app_error", nil, "", http.StatusBadRequest)
+	}
+
+	if len(t.Token) != 26 {
+		return NewAppError("UserAccessToken.IsValid", "model.user_access_token.is_valid.token.app_error", nil, "", http.StatusBadRequest)
+	}
+
+	if !IsValidId(t.UserId) {
+		return NewAppError("UserAccessToken.IsValid", "model.user_access_token.is_valid.user_id.app_error", nil, "", http.StatusBadRequest)
+	}
+
+	if len(t.Description) > 255 {
+		return NewAppError("UserAccessToken.IsValid", "model.user_access_token.is_valid.description.app_error", nil, "", http.StatusBadRequest)
+	}
+
+	return nil
+}
+
+func (t *UserAccessToken) PreSave() {
+	t.Id = NewId()
+	t.IsActive = true
+}