fix(scrolling): enhance and simplify scrolling (#3028)

The previous scrolling implementation (#2687) moved the result selection
by one item at a time, which isn't technically scrolling (ie. moving the
view) and feels quite slow.

Let the neovim builtin scrolling do its thing, so using the scroll wheel
feels like scrolling and is functionally scrolling, too. Scrolling does
not move the selection so after scrolling it typically makes sense to
click. Moving the selection with keyboard takes you back to where you
were. This is in line with typical desktop user interfaces.

lua/telescope/mappings.lua

@@ -133,26 +133,6 @@ local mappings = {}
 mappings.default_mappings = config.values.default_mappings
   or {
     i = {
-      ["<ScrollWheelDown>"] = {
-        actions.mouse_scroll_up,
-        type = "action",
-        opts = { expr = true },
-      },
-      ["<ScrollWheelUp>"] = {
-        actions.mouse_scroll_down,
-        type = "action",
-        opts = { expr = true },
-      },
-      ["<ScrollWheelLeft>"] = {
-        actions.mouse_scroll_right,
-        type = "action",
-        opts = { expr = true },
-      },
-      ["<ScrollWheelRight>"] = {
-        actions.mouse_scroll_left,
-        type = "action",
-        opts = { expr = true },
-      },
       ["<LeftMouse>"] = {
         actions.mouse_click,
         type = "action",
@@ -201,26 +181,6 @@ mappings.default_mappings = config.values.default_mappings
       ["<C-j>"] = actions.nop,
     },
     n = {
-      ["<ScrollWheelDown>"] = {
-        actions.mouse_scroll_up,
-        type = "action",
-        opts = { expr = true },
-      },
-      ["<ScrollWheelUp>"] = {
-        actions.mouse_scroll_down,
-        type = "action",
-        opts = { expr = true },
-      },
-      ["<ScrollWheelLeft>"] = {
-        actions.mouse_scroll_right,
-        type = "action",
-        opts = { expr = true },
-      },
-      ["<ScrollWheelRight>"] = {
-        actions.mouse_scroll_left,
-        type = "action",
-        opts = { expr = true },
-      },
       ["<LeftMouse>"] = {
         actions.mouse_click,
         type = "action",