[FIX] website: prevent race condition on snippet_editor_panel_options

Before this commit this tour was often failing. It seems to be because
there were some requests still being executed / received after the test
was marked as successful and browser getting killed.

According to the logs, even when the tour is actually not failing, there
is still some unexpected requests going on.

With this commit, saving and waiting the edit mode to be exited will
prevent all those requests issues, as it seems like the requests done
after exiting edit mode are all awaited before marking the test as
successfull.

== Before the fix success case ==
- Tour snippet_editor_panel_options on step: 'The text toolbar should still be visible, and the text still selected. (trigger: #oe_snippets .o_we_customize_panel > #o_we_editor_toolbar_container)'
- GET /website/static/src/img/snippets_options/header_template_default.svg HTTP/1.1" 200 - 0 0.000 0.003
- [Same GET for 10 other header templates]
- test successful
- Session expired
- POST /website/theme_customize_data_get HTTP/1.1" 200 - 3 0.001 0.003
- [2 lines above x10]
- Deleting cookies and clearing local storage
- Navigating to: "about:blank"
- Navigation result: {'frameId': 'A538603CC37A4E9EBA99B8624C1CD34E', 'loaderId': '9187051DD3D9477FA4EDEB1A544D584E'}
- Waiting for frame 'A538603CC37A4E9EBA99B8624C1CD34E' to stop loading
- waiting for threads: [<Thread(odoo.service.http.request.139669352166976, started 139669352166976)>]

== Before the fix error case ==
- Tour snippet_editor_panel_options on step: 'The text toolbar should still be visible, and the text still selected. (trigger: #oe_snippets .o_we_customize_panel > #o_we_editor_toolbar_container)'
- GET /website/static/src/img/snippets_options/header_template_sidebar.svg HTTP/1.1" 200 - 0 0.000 0.004
- [Same GET for 10 other header templates]
- test successful
- GET /web/static/img/smile.svg HTTP/1.1" 200 - 0 0.000 0.001
- GET /web/static/img/spin.svg HTTP/1.1" 200 - 0 0.000 0.001
- Failed to fetch
- Asking for screenshot
- Trying to set result to failed (TypeError: Failed to fetch) but found the future settled (<Future at 0x7f8fa1a25120 state=finished returned bool>)
- Deleting cookies and clearing local storage
- Screenshot in: /data/build/tests/36222061-master-all_no_autotag/screenshots/sc_20230513_220042_739175_TestUi.png
- Navigating to: "about:blank"
- Navigation result: {'frameId': 'E1A779132E972A440E5FE892BBBC9FEC', 'loaderId': '822ACED443DB0C84F57DD4A1FF451D5B'}
- Waiting for frame 'E1A779132E972A440E5FE892BBBC9FEC' to stop loading
- waiting for threads: [<Thread(odoo.service.http.request.140254747010624, started 140254747010624)>]

== After the fix case ==
- Tour snippet_editor_panel_options on step: 'iframe body:not(.editor_enable)'
- GET /web/static/img/spin.svg HTTP/1.1" 200 - 0 0.000 0.003
- POST /website/theme_customize_data_get HTTP/1.1" 200 - 8 0.002 0.035
- [Many other POST/GET requests]
- test successful
- Deleting cookies and clearing local storage
- Navigating to: "about:blank"
- Navigation result: {'frameId': '4B87BC8A50A3FEBD7D508394DD5BDB19', 'loaderId': '7CCB3B6434B52B456A1AA470C3CFA1BF'}
- Waiting for frame '4B87BC8A50A3FEBD7D508394DD5BDB19' to stop loading
- waiting for threads: [<Thread(odoo.service.http.request.139744500471360, started 139744500471360)>]

runbot-15312

closes odoo/odoo#121635

Signed-off-by: Xavier Dollé (xdo) <xdo@odoo.com>

addons/website/static/tests/tours/snippet_editor_panel_options.js

@@ -147,4 +147,6 @@ wTourUtils.dragNDrop({
             console.error("The paragraph text selection was lost.");
         }
     },
-}]);
+},
+...wTourUtils.clickOnSave(),
+]);