feat: Allow usage of an absolute path for partitions used in a session (#37604)

* Allow an absolute path to be used for creating sessions

Allows an absolute path to be used for creating sessions
by adding the session.fromPath() API.

* Fixup! Clarify that an emptry string is not permitted as a parameter to fromPath()

shell/browser/api/electron_api_session.h

@@ -82,6 +82,12 @@ class Session : public gin::Wrappable<Session>,
                                             const std::string& partition,
                                             base::Value::Dict options = {});
 
+  // Gets the Session based on |path|.
+  static absl::optional<gin::Handle<Session>> FromPath(
+      v8::Isolate* isolate,
+      const base::FilePath& path,
+      base::Value::Dict options = {});
+
   ElectronBrowserContext* browser_context() const { return browser_context_; }
 
   // gin::Wrappable