Umbraco-CMS: Custom view for block list editor returns 404 if placed in Views folder

@nielslyngsoe I think it is better than what we have now and avoiding this error with custom views inside ~/Views folder. I can always be improved later then 👍

and probably some update in the documentation recommeding placing custom views in e.g. App_Plugins or at root level.

Maybe something like this for now? I can still select html view in App_Plugins and at root level, but not in Views folder (or the other blacklisted folders).

vm.addViewForBlock = function(block) {
    localizationService.localize("blockEditor_headlineAddCustomView").then(function (localizedTitle) {

        const filePicker = {
            title: localizedTitle,
            section: "settings",
            treeAlias: "files",
            entityType: "file",
            isDialog: true,
            filter: function (i) {
                var excludedFolders = ["App_Data", "Media", "Umbraco", "Views"];
                var rootFolderName = i.path === "-1" ? i.name : i.parentId.split("/")[0];

                if (excludedFolders.includes(rootFolderName)) {
                    return true;
                }

                return !(i.name.indexOf(".html") !== -1);
            },
            filterCssClass: "not-allowed",
            select: function (node) {
                const filepath = decodeURIComponent(node.id.replace(/\+/g, " "));
                block.view = "~/" + filepath;
                editorService.close();
            },
            close: function () {
                editorService.close();
            }
        };
        editorService.treePicker(filePicker);

    });
};