[CLD-7421][CLD-7420] Deprecate Self Serve: First Pass (#26668)

* Deprecate Self Serve: First Pass

* Fix ci

* Fix more ci

* Remmove outdated server tests

* Fix a missed spot opening purchase modal in Self Hosted

* Fix i18n

* Clean up some more server code, fix webapp test

* Fix alignment of button

* Fix linter

* Fix i18n server side

* Add back translation

* Remove client functions

* Put back client functions

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Co-authored-by: Mattermost Build <build@mattermost.com>

webapp/channels/src/plugins/export.js

@@ -11,7 +11,6 @@ import ChannelMembersModal from 'components/channel_members_modal';
 import {openPricingModal} from 'components/global_header/right_controls/plan_upgrade_button';
 import {useNotifyAdmin} from 'components/notify_admin_cta/notify_admin_cta';
 import PostMessagePreview from 'components/post_view/post_message_preview';
-import PurchaseModal from 'components/purchase_modal';
 import StartTrialFormModal from 'components/start_trial_form_modal';
 import ThreadViewer from 'components/threading/thread_viewer';
 import Timestamp from 'components/timestamp';
@@ -82,7 +81,6 @@ window.openPricingModal = () => openPricingModal;
 // guarantee better compatibility.
 window.Components = {
     Textbox,
-    PurchaseModal,
     Timestamp,
     ChannelInviteModal,
     ChannelMembersModal,