themes: Improve light theme selections/quotes/stars/times/names.

* Use a consistent black-text/green-background for selections
* Change the color background for blockquote to be legible
* Adjust background of date/time and star-status to match light theme
* Simplify style of name (message author)

Author: neiljp

zulipterminal/config/themes.py

@@ -135,30 +135,30 @@
     ],
     'light': [
         (None,           'black',           'white'),
-        ('selected',     'white',           'dark blue'),
-        ('msg_selected', 'black',           'light gray'),
+        ('selected',     'black',           'light green'),
+        ('msg_selected', 'black',           'light green'),
         ('header',       'white',           'dark blue',  'bold'),
         ('custom',       'white',           'dark blue',  'underline'),
         ('content',      'black',           'light gray', 'standout'),
-        ('name',         'black',           'light gray', 'bold'),
+        ('name',         'dark green',      'white', 'bold'),
         ('unread',       'dark gray',       'light gray'),
         ('active',       'light green',     'dark gray'),
         ('idle',         'yellow',          'dark gray'),
         ('offline',      'white',           'dark gray'),
         ('inactive',     'white',           'dark gray'),
         ('title',        'white, bold',     'dark gray'),
-        ('time',         'white',           'dark gray'),
+        ('time',         'dark blue',           'white'),
         ('bar',          'white',           'dark gray'),
         ('help',         'white',           'dark gray'),
         ('emoji',        'light magenta',   'light gray'),
         ('reaction',     'light magenta, bold',   'light gray'),
         ('span',         'light red, bold', 'light gray'),
         ('link',         'dark blue',       'light gray'),
-        ('blockquote',   'brown',           'dark gray'),
+        ('blockquote',   'black',           'brown'),
         ('code',         'dark gray',       'white'),
         ('bold',         'white, bold',     'dark gray'),
         ('footer',       'white',           'dark red',   'bold'),
-        ('starred',      'light red, bold', 'dark gray'),
+        ('starred',      'light red, bold', 'white'),
         ('category',     'dark gray, bold', 'light gray'),
     ],
     'blue': [