chore(dep-resolution): add dependency resolution errors to core error…

… type (#302)

As part of the ongoing lockfileless work, we aim to integrate errors
that occur during dependency resolution into the error framework that
the rest of the CLI uses. This PR adds dependency resolution errors as
an error type.

Dependency _parser_ errors remain as their own type for now, but in the
future may be integrated as well by adding them as a variant of
`DependencyResolutionError`.

- [x] I ran `make setup && make` to update the generated code after
editing a `.atd` file (TODO: have a CI check)
- [x] I made sure we're still backward compatible with old versions of
the CLI.
For example, the Semgrep backend need to still be able to *consume* data
generated
	  by Semgrep 1.17.0.
See
https://atd.readthedocs.io/en/latest/atdgen-tutorial.html#smooth-protocol-upgrades

semgrep_output_v1.atd

@@ -511,6 +511,8 @@ type error_type
    * *)
   | PatternParseError0 <json name="Pattern parse error">
   | IncompatibleRule0 <json name="Incompatible rule">
+  (* since semgrep 1.94.0 *)
+  | DependencyResolutionError of resolution_error
 ] <ocaml repr="classic">
 
 type incompatible_rule
@@ -1846,6 +1848,7 @@ type manifest = {
 }
 
 type resolution_error
+    <ocaml attr="deriving show">
     <python decorator="dataclass(frozen=True)"> = [
     | UnsupportedManifest
     | MissingRequirement of string
@@ -1854,6 +1857,7 @@ type resolution_error
 ]
 
 type resolution_cmd_failed
+  <ocaml attr="deriving show">
   <python decorator="dataclass(frozen=True)"> = {
     command: string;
     message: string;