Move internal packages to an internal folder

For reference: https://go.dev/doc/go1.4#internalpackages

internal/ui/view/view.go

@@ -0,0 +1,47 @@
+// SPDX-FileCopyrightText: Copyright The Miniflux Authors. All rights reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+package view // import "miniflux.app/v2/internal/ui/view"
+
+import (
+	"net/http"
+
+	"miniflux.app/v2/internal/http/request"
+	"miniflux.app/v2/internal/template"
+	"miniflux.app/v2/internal/ui/session"
+	"miniflux.app/v2/internal/ui/static"
+)
+
+// View wraps template argument building.
+type View struct {
+	tpl    *template.Engine
+	r      *http.Request
+	params map[string]interface{}
+}
+
+// Set adds a new template argument.
+func (v *View) Set(param string, value interface{}) *View {
+	v.params[param] = value
+	return v
+}
+
+// Render executes the template with arguments.
+func (v *View) Render(template string) []byte {
+	return v.tpl.Render(template+".html", v.params)
+}
+
+// New returns a new view with default parameters.
+func New(tpl *template.Engine, r *http.Request, sess *session.Session) *View {
+	b := &View{tpl, r, make(map[string]interface{})}
+	theme := request.UserTheme(r)
+	b.params["menu"] = ""
+	b.params["csrf"] = request.CSRF(r)
+	b.params["flashMessage"] = sess.FlashMessage(request.FlashMessage(r))
+	b.params["flashErrorMessage"] = sess.FlashErrorMessage(request.FlashErrorMessage(r))
+	b.params["theme"] = theme
+	b.params["language"] = request.UserLanguage(r)
+	b.params["theme_checksum"] = static.StylesheetBundleChecksums[theme]
+	b.params["app_js_checksum"] = static.JavascriptBundleChecksums["app"]
+	b.params["sw_js_checksum"] = static.JavascriptBundleChecksums["service-worker"]
+	return b
+}