Add additional resource bundle for non-translatable strings

.../main/kotlin/org/briarproject/briar/desktop/ui/BriarUi.kt

...rproject/briar/desktop/utils/InternationalizationUtils.kt

...esktop/src/main/resources/strings/BriarDesktop.properties

...in/resources/strings/BriarDesktopNonTranslated.properties

...top/src/main/resources/strings/BriarDesktop_ar.properties

...top/src/main/resources/strings/BriarDesktop_bg.properties

...top/src/main/resources/strings/BriarDesktop_ca.properties

...top/src/main/resources/strings/BriarDesktop_de.properties

...top/src/main/resources/strings/BriarDesktop_es.properties

...top/src/main/resources/strings/BriarDesktop_fa.properties

...top/src/main/resources/strings/BriarDesktop_fr.properties

...top/src/main/resources/strings/BriarDesktop_gl.properties

...top/src/main/resources/strings/BriarDesktop_he.properties

...top/src/main/resources/strings/BriarDesktop_hu.properties

...top/src/main/resources/strings/BriarDesktop_is.properties

...top/src/main/resources/strings/BriarDesktop_it.properties

...top/src/main/resources/strings/BriarDesktop_ja.properties

...top/src/main/resources/strings/BriarDesktop_ka.properties

...top/src/main/resources/strings/BriarDesktop_ko.properties

...top/src/main/resources/strings/BriarDesktop_lt.properties