Keep selection in SwitchToHelixNormalMode (#41583)

Closes #41125

Release Notes:

- Fixed `SwitchToHelixNormalMode` to keep selection
- Added default keybinds for `SwitchToHelixNormalMode` when in Helix
mode

crates/vim/src/state.rs

@@ -66,12 +66,16 @@ impl Display for Mode {
 }
 
 impl Mode {
-    pub fn is_visual(&self) -> bool {
+    pub fn is_visual(self) -> bool {
         match self {
             Self::Visual | Self::VisualLine | Self::VisualBlock | Self::HelixSelect => true,
             Self::Normal | Self::Insert | Self::Replace | Self::HelixNormal => false,
         }
     }
+
+    pub fn is_helix(self) -> bool {
+        matches!(self, Mode::HelixNormal | Mode::HelixSelect)
+    }
 }
 
 impl Default for Mode {
@@ -990,7 +994,7 @@ pub struct SearchState {
     pub prior_selections: Vec<Range<Anchor>>,
     pub prior_operator: Option<Operator>,
     pub prior_mode: Mode,
-    pub helix_select: bool,
+    pub is_helix_regex_search: bool,
 }
 
 impl Operator {