tools: remove broken structured.py (#812)

This script was previously used in Electrum but no more.

So since this script doesn't even parse the output of
extract-formats.py any more, just remove it.

tools/structured.py

@@ -1,51 +0,0 @@
-from io import StringIO
-import glob
-import collections
-import json
-
-formats = __import__("extract-formats")
-
-
-class Options(object):
-    output_types = True
-    output_fields = True
-    check_alignment = False
-
-
-options = Options()
-csv = []
-
-output = StringIO()
-for i in sorted(glob.glob("../??-*.md")):
-    with open(i) as f:
-        formats.main(options, output=output, lines=f.readlines())
-        csvstr = output.getvalue().strip()
-        if csvstr == "":
-            continue
-        csv += csvstr.split("\n")
-
-resmap = collections.OrderedDict()
-
-currentmsgname = None
-currentmsgfields = {}
-typenum = None
-for line in csv:
-    parts = line.split(",")
-    if len(parts) == 2:
-        if currentmsgname is not None:
-            resmap[currentmsgname] = collections.OrderedDict(
-                [("type", typenum), ("payload", currentmsgfields)])
-        currentmsgfields = collections.OrderedDict()
-        currentmsgname = parts[0]
-        typenum = parts[1]
-        continue
-    assert currentmsgname == parts[0], line
-    assert len(parts) in [4, 5], line
-    position = parts[1]
-    length = parts[3]
-    fieldname = parts[2]
-    currentmsgfields[fieldname] = {"position": position, "length": length}
-    if len(parts) == 5: currentmsgfields[fieldname]["feature"] = parts[4]
-
-if __name__ == "__main__":
-    print(json.dumps(resmap, indent=True))