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/terms_of_service_test.go

@@ -0,0 +1,35 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package model
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestTermsOfServiceIsValid(t *testing.T) {
+	s := TermsOfService{}
+
+	assert.NotNil(t, s.IsValid(), "should be invalid")
+
+	s.Id = NewId()
+	assert.NotNil(t, s.IsValid(), "should be invalid")
+
+	s.CreateAt = GetMillis()
+	assert.NotNil(t, s.IsValid(), "should be invalid")
+
+	s.UserId = NewId()
+	assert.Nil(t, s.IsValid(), "should be valid")
+
+	s.Text = strings.Repeat("0", PostMessageMaxRunesV2+1)
+	assert.NotNil(t, s.IsValid(), "should be invalid")
+
+	s.Text = strings.Repeat("0", PostMessageMaxRunesV2)
+	assert.Nil(t, s.IsValid(), "should be valid")
+
+	s.Text = "test"
+	assert.Nil(t, s.IsValid(), "should be valid")
+}