Add jsua for --mode=browser binds

Works like jsb but preserves the 'user action' so
it can be used to open/close the sidebar, open
downloaded files etc.

Example usage:

`:bind --mode=browser <C-.> jsua browser.sidebarAction.close()`

src/background/commands.ts

@@ -6,12 +6,14 @@ import * as controller from "@src/lib/controller"
 function makelistener(commands: Array<browser.commands.Command>) {
     return (command_name: string) => {
         const command = commands.filter(c => c.name == command_name)[0]
-        const exstring = config.get(
+        const [excmd, ...exargs] = config
+            .get(
                 "browsermaps",
                 keyseq.mozMapToMinimalKey(command.shortcut).toMapstr(),
             )
-        if (exstring in useractions) return useractions[exstring]()
+            .split(" ")
-        return controller.acceptExCmd(exstring)
+        if (excmd in useractions) return useractions[excmd](...exargs)
+        return controller.acceptExCmd([excmd, ...exargs].join(" "))
     }
 }
 

src/background/user_actions.ts

@@ -43,7 +43,12 @@ function sidebartoggle() {
     return browser.sidebarAction.toggle()
 }
 
-export const useractions: Record<string, () => void> = {
+function jsua(...args: string[]) {
+    return eval(args.join(" "))
+}
+
+export const useractions: Record<string, (...args: string[]) => void> = {
     escapehatch,
     sidebartoggle,
+    jsua,
 }