net: reconsiderblock activates the most-work chain

changelog.d/reconsider-most-work.md

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+Fixed
+
+- **`reconsiderblock` activates the most-work chain, as Core does.** Each
+  restored path used to be re-applied on its own, so a chain that only
+  outweighed the tip as a whole stayed inactive. A branch that fails to
+  connect no longer stops the next one. A restored leaf that loses, and
+  was connected before, now stays a valid fork, so a later
+  `invalidateblock` can return to it. That later walk keeps the usual
+  10,000-block side-branch limit; only the reconsider itself walks
+  restored blocks past it.