Fix evidence refs with spaces

For some reason, MS Word ignores bookmarks with spaces in them. I can't
find any restrictions on bookmark names in the spec. This patch replaces
spaces with underscores.

This also adds some bookmark ID tracking rather than using ID "0" for
every bookmark.

ghostwriter/modules/reportwriter/richtext/docx.py

@@ -117,13 +117,14 @@ def _tag_h(self, el, **kwargs):
             run = heading_paragraph.runs[0]
             tag = run._r
             start = docx.oxml.shared.OxmlElement("w:bookmarkStart")
-            start.set(docx.oxml.ns.qn("w:id"), "0")
+            start.set(docx.oxml.ns.qn("w:id"), str(self.current_bookmark_id))
             start.set(docx.oxml.ns.qn("w:name"), el.attrs["id"])
             tag.append(start)
             end = docx.oxml.shared.OxmlElement("w:bookmarkEnd")
-            end.set(docx.oxml.ns.qn("w:id"), "0")
+            end.set(docx.oxml.ns.qn("w:id"), str(self.current_bookmark_id))
             end.set(docx.oxml.ns.qn("w:name"), el.attrs["id"])
             tag.append(end)
+            self.current_bookmark_id += 1
 
     tag_h1 = _tag_h
     tag_h2 = _tag_h
@@ -296,6 +297,7 @@ def __init__(
         self.title_case_exceptions = title_case_exceptions
         self.border_color_width = border_color_width
         self.plural_acronym_pattern = re.compile(r"^[^a-z]+(:?s|'s)$")
+        self.current_bookmark_id = 1000 # Hopefully won't conflict with templates
 
     def text(self, el, *, par=None, **kwargs):
         if par is not None and getattr(par, "_gw_is_caption", False):
@@ -374,8 +376,8 @@ def make_caption(self, par, label: str, ref: str | None = None):
         # Start a bookmark run with the figure label
         p = par._p
         bookmark_start = OxmlElement("w:bookmarkStart")
-        bookmark_start.set(qn("w:name"), ref)
-        bookmark_start.set(qn("w:id"), "0")
+        bookmark_start.set(qn("w:name"), ref.replace(" ", "_"))
+        bookmark_start.set(qn("w:id"), str(self.current_bookmark_id))
         p.append(bookmark_start)
 
         # Add the figure label
@@ -414,9 +416,11 @@ def make_caption(self, par, label: str, ref: str | None = None):
         # End the bookmark after the number
         p = par._p
         bookmark_end = OxmlElement("w:bookmarkEnd")
-        bookmark_end.set(qn("w:id"), "0")
+        bookmark_end.set(qn("w:id"), str(self.current_bookmark_id))
         p.append(bookmark_end)
 
+        self.current_bookmark_id += 1
+
     def make_evidence(self, par, evidence):
         file_path = settings.MEDIA_ROOT + "/" + evidence["path"]
         if not os.path.exists(file_path):
@@ -528,7 +532,7 @@ def make_cross_ref(self, par, ref: str):
         run = par.add_run()
         r = run._r
         instrText = OxmlElement("w:instrText")
-        instrText.text = ' REF "_Ref{}" \\h '.format(ref.replace("\\", "\\\\").replace('"', '\\"'))
+        instrText.text = ' REF "_Ref{}" \\h '.format(ref.replace("\\", "\\\\").replace('"', '\\"').replace(" ", "_"))
         r.append(instrText)
 
         # An optional ``separate`` value to enforce a space between label and number