Add check for non-comparable types under `set` and `ticket`

Motivation and Context

Currently LIGO fails with an error on type-checking when compiling a contract that applies set or ticket to a non-comparable type:

$ cat not_comparable.mligo 
let main ((_u, s) : (int set) set * unit) : operation list * unit = ([] : operation list), s
$ ligo compile contract not_comparable.mligo 
Error(s) occurred while type checking the contract:
At (unshown) location 2, ill formed type:
  1: { parameter (set (set int)) ;
  2:   storage unit ;
  3:   code { CDR ; NIL operation ; PAIR } }
At line 1 characters 17 to 25,
comparable type expected.Type set int is not comparable.

This is not a very helpful message for the user, as the locations warned in the error refer to Michelson and not to LIGO.

Description

This MR introduces a check at 15-self_mini_c.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Performance improvement (non-breaking change that improves performance)
• None (change with no changelog)

Changelog

Before change

$ ligo compile contract not_comparable.mligo 
Error(s) occurred while type checking the contract:
At (unshown) location 2, ill formed type:
  1: { parameter (set (set int)) ;
  2:   storage unit ;
  3:   code { CDR ; NIL operation ; PAIR } }
At line 1 characters 17 to 25,
comparable type expected.Type set int is not comparable.

After change

$ ligo compile contract not_comparable.mligo 
File "not_comparable.mligo", line 1, characters 21-28:
  1 | let main ((_u, s) : (int set) set * unit) : operation list * unit = ([] : operation list), s

The set constructor needs a comparable type argument, but it was given a non-comparable one.

Checklist:

• Changes follow the existing coding style (use dune @fmt to check).
• Tests for the changes have been added (for bug fixes / feature).
• Documentation has been updated.
• Changelog description has been added (if appropriate).
• Examples in changed behaviour have been added to the changelog (for breaking change / feature).

src/bin/expect_tests/contract_tests.ml

@@ -1155,11 +1155,21 @@ let%expect_test _ =
 
 let%expect_test _ =
   run_ligo_bad [ "compile" ; "contract" ; bad_contract "not_comparable.mligo" ] ;
-  [%expect{| "Tezos.self" must be used directly and cannot be used via another function. |}]
+  [%expect{|
+    File "../../test/contracts/negative/not_comparable.mligo", line 1, characters 21-28:
+      1 | let main ((_u, s) : (int set) set * unit) : operation list * unit = ([] : operation list), s
+      2 |
+
+    The set constructor needs a comparable type argument, but it was given a non-comparable one. |}]
 
 let%expect_test _ =
   run_ligo_bad [ "compile" ; "contract" ; bad_contract "not_comparable.mligo" ; "-e" ; "main2" ] ;
-  [%expect{| "Tezos.self" must be used directly and cannot be used via another function. |}]
+  [%expect{|
+    File "../../test/contracts/negative/not_comparable.mligo", line 3, characters 22-29:
+      2 |
+      3 | let main2 ((_u, s) : (int set) ticket * unit) : operation list * unit = ([] : operation list), s
+
+    The ticket constructor needs a comparable type argument, but it was given a non-comparable one. |}]
 
 let%expect_test _ =
   run_ligo_good [ "compile" ; "storage" ; contract "big_map.ligo" ; "(big_map1,unit)" ] ;