feat(plugins): extensive plugin api (#2516)

* feat(plugins): add our entire API

* style(fmt): rustfmt

* fix(detach): make it work again

67 files changed, 5430 insertions, 568 deletions

diff --git a/default-plugins/fixture-plugin-for-tests/src/main.rs b/default-plugins/fixture-plugin-for-tests/src/main.rs
index 7e4139f55..2107137d1 100644
--- a/default-plugins/fixture-plugin-for-tests/src/main.rs
+++ b/default-plugins/fixture-plugin-for-tests/src/main.rs
@@ -38,10 +38,10 @@ impl ZellijPlugin for State {
     fn load(&mut self) {
         subscribe(&[
             EventType::InputReceived,
+            EventType::Key,
             EventType::SystemClipboardFailure,
             EventType::CustomMessage,
             EventType::FileSystemCreate,
-            EventType::FileSystemRead,
             EventType::FileSystemUpdate,
             EventType::FileSystemDelete,
         ]);
@@ -49,6 +49,142 @@ impl ZellijPlugin for State {
 
     fn update(&mut self, event: Event) -> bool {
         match &event {
+            Event::Key(key) => match key {
+                Key::Char('a') => {
+                    switch_to_input_mode(&InputMode::Tab);
+                },
+                Key::Char('b') => {
+                    new_tabs_with_layout(
+                        "layout {
+                        tab {
+                            pane
+                            pane
+                        }
+                        tab split_direction=\"vertical\" {
+                            pane
+                            pane
+                        }
+                    }",
+                    );
+                },
+                Key::Char('c') => new_tab(),
+                Key::Char('d') => go_to_next_tab(),
+                Key::Char('e') => go_to_previous_tab(),
+                Key::Char('f') => {
+                    let resize = Resize::Increase;
+                    resize_focused_pane(resize)
+                },
+                Key::Char('g') => {
+                    let resize = Resize::Increase;
+                    let direction = Direction::Left;
+                    resize_focused_pane_with_direction(resize, direction);
+                },
+                Key::Char('h') => focus_next_pane(),
+                Key::Char('i') => focus_previous_pane(),
+                Key::Char('j') => {
+                    let direction = Direction::Left;
+                    move_focus(direction)
+                },
+                Key::Char('k') => {
+                    let direction = Direction::Left;
+                    move_focus_or_tab(direction)
+                },
+                Key::Char('l') => detach(),
+                Key::Char('m') => edit_scrollback(),
+                Key::Char('n') => {
+                    let bytes = vec![102, 111, 111];
+                    write(bytes)
+                },
+                Key::Char('o') => {
+                    let chars = "foo";
+                    write_chars(chars);
+                },
+                Key::Char('p') => toggle_tab(),
+                Key::Char('q') => move_pane(),
+                Key::Char('r') => {
+                    let direction = Direction::Left;
+                    move_pane_with_direction(direction)
+                },
+                Key::Char('s') => clear_screen(),
+                Key::Char('t') => scroll_up(),
+                Key::Char('u') => scroll_down(),
+                Key::Char('v') => scroll_to_top(),
+                Key::Char('w') => scroll_to_bottom(),