debugger: Filter out debug scenarios with invalid Adapters from debug picker (#35744)

I also removed a debug assertion that wasn't true when a debug session
was restarting through a request, because there wasn't a booting task
Zed needed to run before the session.

I renamed SessionState::Building to SessionState::Booting as well,
because building implies that we're building code while booting the
session covers more cases and is more accurate.

Release Notes:

- debugger: Filter out more invalid debug configurations from the debug
picker

Co-authored-by: Remco Smits <djsmits12@gmail.com>

crates/dap/src/adapters.rs

@@ -74,6 +74,12 @@ impl Borrow<str> for DebugAdapterName {
     }
 }
 
+impl Borrow<SharedString> for DebugAdapterName {
+    fn borrow(&self) -> &SharedString {
+        &self.0
+    }
+}
+
 impl std::fmt::Display for DebugAdapterName {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(&self.0, f)

crates/dap/src/registry.rs

@@ -87,7 +87,7 @@ impl DapRegistry {
         self.0.read().adapters.get(name).cloned()
     }
 
-    pub fn enumerate_adapters(&self) -> Vec<DebugAdapterName> {
+    pub fn enumerate_adapters<B: FromIterator<DebugAdapterName>>(&self) -> B {
         self.0.read().adapters.keys().cloned().collect()
     }
 }