Add plural formatting, translate and tweak some accessibility strings in composer (#7997)

* add plural formatting and translate accessibility strings

* tweak accessibility label and add comments for translators

* fix

* tweak comments

* make label conditionally plural

* rm stray bracket

* try to fix prettier

* nope

* lint

* more lint

* prettier

---------

Co-authored-by: Hailey <me@haileyok.com>

src/view/com/composer/labels/LabelsBtn.tsx

@@ -113,8 +113,8 @@ function DialogInner({
           </Text>
           <Text style={[t.atoms.text_contrast_medium, a.leading_snug]}>
             <Trans>
-              Please add any content warning labels that are applicable for
-              the media you are posting.
+              Please add any content warning labels that are applicable for the
+              media you are posting.
             </Trans>
           </Text>
         </View>