fix: Include figure prefix in name before rendering text

Fixes #ietf-tools#961

tests/valid/draft-miek-test.pages.text

@@ -1102,8 +1102,8 @@ A.10.  Figure tests
    This is a figure
    This is a figure
 
-      Figure 4: This is the caption, with text in `typewriter`. Which
-      isnt converted to a <spanx> style, because this is copied as-is.
+    Figure 4: This is the caption, with text in `typewriter`. Which isnt
+        converted to a <spanx> style, because this is copied as-is.
 
    And how a figure that is not centered, do to using figure and not
    Figure.

tests/valid/draft-miek-test.text

@@ -930,8 +930,8 @@ A.10.  Figure tests
    This is a figure
    This is a figure
 
-      Figure 4: This is the caption, with text in `typewriter`. Which
-      isnt converted to a <spanx> style, because this is copied as-is.
+    Figure 4: This is the caption, with text in `typewriter`. Which isnt
+        converted to a <spanx> style, because this is copied as-is.
 
    And how a figure that is not centered, do to using figure and not
    Figure.

tests/valid/draft-miek-test.txt

@@ -1102,8 +1102,8 @@ A.10.  Figure tests
    This is a figure
    This is a figure
 
-      Figure 4: This is the caption, with text in `typewriter`. Which
-      isnt converted to a <spanx> style, because this is copied as-is.
+    Figure 4: This is the caption, with text in `typewriter`. Which isnt
+        converted to a <spanx> style, because this is copied as-is.
 
    And how a figure that is not centered, do to using figure and not
    Figure.

xml2rfc/writers/text.py

@@ -1736,11 +1736,20 @@ def render_figure(self, e, width, **kwargs):
         pn = e.get('pn')
         num = pn.split('-')[1].capitalize()
         children = e.getchildren()
-        title = "Figure %s" % (num, )
+        title = "Figure {}".format(num)
         if len(children) and children[0].tag == 'name':
             name = children[0]
+            if name.text:
+                name.text = "{prefix}{joiner} {text}".format(
+                                prefix=title,
+                                joiner=kwargs["joiners"]["name"].join,
+                                text=name.text)
+            else:
+                name.text = "{prefix}{joiner} ".format(
+                                prefix=title,
+                                joiner=kwargs["joiners"]["name"].join)
             children = children[1:]
-            title = self.tjoin(title, name, width, **kwargs)
+            title = self.render(name, width, **kwargs)
         lines = []
         for c in children:
             lines = self.ljoin(lines, c, width, **kwargs)