[ fix #3448 ] Fix %search in constraint

[spcfox]

Description

Added parameters to constraint hints to fix #3448

Should this change go in the CHANGELOG?

• If this is a fix, user-facing change, a compiler change, or a new paper
  implementation, I have updated CHANGELOG_NEXT.md (and potentially also
  CONTRIBUTORS.md).

[spcfox]

%search still can't find implicitly bound parameters:

X : Type
data Y : X -> Type

failing "While processing constructor MkZ. Can't find an implementation for X"
  interface Y %search => Z (y : Y x) where
    constructor MkZ

interface Y x => Z (y : Y x) where
  constructor MkZ

0 getX : Z y => X
getX = %search

I expected that adding pNames would fix it, but no

[spcfox]

Ok, it's not a problem with interfaces

X : Type
data Y : X -> Type

failing "While processing constructor MkZ. Can't find an implementation for X"
  interface Y %search => Z (y : Y x) where
    constructor MkZ

-- The interface is elaborated into such data
failing "While processing constructor MkZ. Can't find an implementation for X"
  data Z : Y x -> Type where
    MkZ : {y : Y x} -> Y %search => Z y

I created issue #3452 for this

[dunhamsteve]

This also fixes the issue that I was addressing in #3052, where this would not compile:

%unbound_implicits off
interface Foo a where
interface Foo a => Bar (a : Type) where

The issue there was that the constraints were relying on the unbound implicits mechanism to pick up the a, while all of the other generated code for interfaces was explicitly adding the parameters.