Fix ordering for force-sort-within-sections (#8665)

Fixes #8661 

## Summary

Imports like `from x import y` don't have an "asname" for the module, so
they were placed before imports like `import x as w` since `None` <
`Some(s)` for any string s.
The fix is to first sort by `first_alias`, since it's `None` for `import
x as w`, and then by `asname`.

## Test Plan

I included the example from the issue to avoid future regressions.

crates/ruff_linter/resources/test/fixtures/isort/force_sort_within_sections_with_as_names.py

@@ -0,0 +1,5 @@
+import encodings
+from datetime import timezone as tz
+from datetime import timedelta
+import datetime as dt
+import datetime

crates/ruff_linter/src/rules/isort/mod.rs

@@ -697,6 +697,7 @@ mod tests {
     }
 
     #[test_case(Path::new("force_sort_within_sections.py"))]
+    #[test_case(Path::new("force_sort_within_sections_with_as_names.py"))]
     fn force_sort_within_sections(path: &Path) -> Result<()> {
         let snapshot = format!("force_sort_within_sections_{}", path.to_string_lossy());
         let mut diagnostics = test_path(

crates/ruff_linter/src/rules/isort/snapshots/ruff_linter__rules__isort__tests__force_sort_within_sections_force_sort_within_sections_with_as_names.py.snap

@@ -0,0 +1,25 @@
+---
+source: crates/ruff_linter/src/rules/isort/mod.rs
+---
+force_sort_within_sections_with_as_names.py:1:1: I001 [*] Import block is un-sorted or un-formatted
+  |
+1 | / import encodings
+2 | | from datetime import timezone as tz
+3 | | from datetime import timedelta
+4 | | import datetime as dt
+5 | | import datetime
+  |
+  = help: Organize imports
+
+ℹ Safe fix
+  1 |+import datetime
+  2 |+import datetime as dt
+  3 |+from datetime import timedelta
+  4 |+from datetime import timezone as tz
+1 5 | import encodings
+2   |-from datetime import timezone as tz
+3   |-from datetime import timedelta
+4   |-import datetime as dt
+5   |-import datetime
+
+

crates/ruff_linter/src/rules/isort/sorting.rs

@@ -78,8 +78,8 @@ pub(crate) struct ModuleKey<'a> {
     force_to_top: Option<bool>,
     maybe_lowercase_name: Option<NatOrdStr<'a>>,
     module_name: Option<NatOrdStr<'a>>,
-    asname: Option<NatOrdStr<'a>>,
     first_alias: Option<MemberKey<'a>>,
+    asname: Option<NatOrdStr<'a>>,
 }
 
 impl<'a> ModuleKey<'a> {
@@ -110,8 +110,8 @@ impl<'a> ModuleKey<'a> {
             force_to_top,
             maybe_lowercase_name,
             module_name,
-            asname,
             first_alias,
+            asname,
         }
     }
 }