Make file separator configurable

[michalvavrik]

We encountered issue in Quarkus when we have Windows-specific paths and had to work around that. Please see quarkusio/quarkus#50490 for more information.

[michalvavrik]

@phillip-kruger I didn't test it because I am not yet familiar with how to push it to some local repo and let Quarkus pick it up, but the idea is that Quarkus would do:

<qui-directory-tree id="directoryTree" class="files"
                        .directory="${this._workspaceTreeNames}"
                       .fileSeparator="${this._fileSeparator}" // <----- this part is new
                        header="Source Code"
                        @file-select="${this._onFileSelect}"
                    ></qui-directory-tree>

[phillip-kruger]

Thanks !