Pair TLE lines through the shared decoder and add the changelog fragment

changelog.d/1101-tle-catalog-number-match.md

@@ -0,0 +1,3 @@
+- Skip TLE sets whose line 1 and line 2 carry different catalog numbers, so a
+  spliced catalog cannot pair one satellite's elements with another's; the next
+  valid set still parses (VG31OP, #1101).