[ty] Improve error messages for unresolved attribute diagnostics (#20963)

## Summary

- Type checkers (and type-checker authors) think in terms of types, but
I think most Python users think in terms of values. Rather than saying
that a _type_ `X` "has no attribute `foo`" (which I think sounds strange
to many users), say that "an object of type `X` has no attribute `foo`"
- Special-case certain types so that the diagnostic messages read more
like normal English: rather than saying "Type `<class 'Foo'>` has no
attribute `bar`" or "Object of type `<class 'Foo'>` has no attribute
`bar`", just say "Class `Foo` has no attribute `bar`"

## Test Plan

Mdtests and snapshots updated

crates/ty/tests/cli/python_environment.rs

@@ -30,7 +30,7 @@ fn config_override_python_version() -> anyhow::Result<()> {
     success: false
     exit_code: 1
     ----- stdout -----
-    error[unresolved-attribute]: Type `<module 'sys'>` has no attribute `last_exc`
+    error[unresolved-attribute]: Module `sys` has no member `last_exc`
      --> test.py:5:7
       |
     4 | # Access `sys.last_exc` that was only added in Python 3.12
@@ -962,7 +962,7 @@ fn defaults_to_a_new_python_version() -> anyhow::Result<()> {
     success: false
     exit_code: 1
     ----- stdout -----
-    error[unresolved-attribute]: Type `<module 'os'>` has no attribute `grantpt`
+    error[unresolved-attribute]: Module `os` has no member `grantpt`
      --> main.py:4:1
       |
     2 | import os

crates/ty/tests/file_watching.rs

@@ -1112,11 +1112,11 @@ print(sys.last_exc, os.getegid())
     assert_eq!(diagnostics.len(), 2);
     assert_eq!(
         diagnostics[0].primary_message(),
-        "Type `<module 'sys'>` has no attribute `last_exc`"
+        "Module `sys` has no member `last_exc`"
     );
     assert_eq!(
         diagnostics[1].primary_message(),
-        "Type `<module 'os'>` has no attribute `getegid`"
+        "Module `os` has no member `getegid`"
     );
 
     // Change the python version