test: ensure that a function requiring conversion depends on converter

This test turned out to be a very discerning one. Adding it uncovered
  numerous bugs, large and small, in the TypeDispatcher. The most major
  one was that a Map distinguishes keys by strict equality, and hence
  since every lookup for a cached behavior was using a newly-generated array
  of types, the cache was never being hit. So it looked like methods were
  being updated as dependencies changed, when what was really happening
  was that the behavior was simply being regenerated from scratch on every
  call, which would not be performant as the prototype scaled.
  This bug is now fixed (by switching to a third-party ArrayKeyedMap), along
  with many smaller bugs too numerous to list.

  It should now be feasible to go through Pocomath and add all of the functions
  that depend on numbers and booleans only.

pnpm-lock.yaml

@@ -7,6 +7,10 @@ settings:
 importers:
 
   .:
+    dependencies:
+      array-keyed-map:
+        specifier: ^2.1.3
+        version: 2.1.3
     devDependencies:
       mocha:
         specifier: ^11.1.0
@@ -49,6 +53,9 @@ packages:
   argparse@2.0.1:
     resolution: {integrity: sha512-8+9WqebbFzpX9OR+Wa6O29asIogeRMzcGtAINdpMHHyAg10f05aSFVBbcEqGf/PXw1EjAZ+q2/bEBg3DvurK3Q==}
 
+  array-keyed-map@2.1.3:
+    resolution: {integrity: sha512-JIUwuFakO+jHjxyp4YgSiKXSZeC0U+R1jR94bXWBcVlFRBycqXlb+kH9JHxBGcxnVuSqx5bnn0Qz9xtSeKOjiA==}
+
   balanced-match@1.0.2:
     resolution: {integrity: sha512-3oSeUO0TMV67hN1AmbXsK4yaqU7tjiHlbxRDZOpH0KW9+CeX4bRAaX0Anxt0tx2MrpRpWwQaPwIlISEJhYU5Pw==}
 
@@ -398,6 +405,8 @@ snapshots:
 
   argparse@2.0.1: {}
 
+  array-keyed-map@2.1.3: {}
+
   balanced-match@1.0.2: {}
 
   binary-extensions@2.3.0: {}