Style fixes and additions

Add "border" color to theme and fix spacing in conversation with public key bottom sheet

frontend/Constants/Theme/theme-dark.json

@@ -23,6 +23,7 @@
     "surfaceVariant": "#45464F",
     "onSurfaceVariant": "#C6C6D0",
     "outline": "#8F909A",
+    "border":"#00487F",
     "outlineVariant": "#45464F",
     "shadow": "#000000",
     "scrim": "#000000",

frontend/Pages/ConversationsFeed/index.tsx

@@ -290,6 +290,7 @@ export const ConversationsFeed: React.FC = () => {
           <Text variant='titleLarge'>{t('conversationsFeed.openMessageTitle')}</Text>
           <Text variant='bodyMedium'>{t('conversationsFeed.openMessageDescription')}</Text>
           <TextInput
+            style={styles.input}
             mode='outlined'
             label={t('conversationsFeed.openMessageLabel') ?? ''}
             onChangeText={setSendPubKeyInput}
@@ -348,6 +349,10 @@ const styles = StyleSheet.create({
     right: 16,
     position: 'absolute',
   },
+  input: {
+    marginTop: 16,
+    marginBottom: 16,
+  },
   center: {
     alignContent: 'center',
     textAlign: 'center',