fix(options): handling and overwriting cli opts (#859)

* fix(options): handling ond verwriting cli opts

* previously it was only possible to turn off certain features with a
  command line option, now it is possible to also overwrite this
  behavior in a sane way, for that some breaking changes happened:

  following options got renamed and inverted:
  ```
  disable_mouse_mode -> mouse_mode
  no_pane_frames -> pane_frames
  ```

  following cli options got added:
  ```
  mouse-mode [bool]
  pane-frames [bool]
  simplified-ui [bool]
  ```

  the following cli flag got removed:
  ```
  simplified-ui
  ```

  They can be specified in the following way:
  ```
  zellij options --mouse-mode true
  ```
  in order to enable the mouse mode, even if it is turned off in the
  config file:
  ```
  mouse_mode: false
  ```

  The order is now as follows:
  1. corresponding flag (`disable-mouse-mode`)
  2. corresponding option (`mouse-mode`)
  3. corresponding config option (`mouse_mode`)

* add: options and flags for the same value conflict

* example:
  ```
  zellij options --mouse-mode true --disable-mouse-mode`
  ```
  ```
  $ error: The argument '--mouse-mode <mouse-mode>' cannot be used with '--disable-mouse-mode'
  ```

1 files changed, 1 insertions, 1 deletions

diff --git a/zellij-client/src/input_handler.rs b/zellij-client/src/input_handler.rs
index 0f8a60ff2..3c2495c02 100644
--- a/zellij-client/src/input_handler.rs
+++ b/zellij-client/src/input_handler.rs
@@ -63,7 +63,7 @@ impl InputHandler {
         let mut err_ctx = OPENCALLS.with(|ctx| *ctx.borrow());
         err_ctx.add_call(ContextType::StdinHandler);
         let alt_left_bracket = vec![27, 91];
-        if !self.options.disable_mouse_mode.unwrap_or_default() {
+        if self.options.mouse_mode.unwrap_or(true) {
             self.os_input.enable_mouse();
         }
         loop {