Remove into SelectionEffects from .change_selections (#33554)

In #32656 I generalized the argument to change selections to allow
controling both the scroll and the nav history (and the completion
trigger).

To avoid conflicting with ongoing debugger cherry-picks I left the
argument as an `impl Into<>`, but I think it's clearer to make callers
specify what they want here.

I converted a lot of `None` arguments to `SelectionEffects::no_scroll()`
to be exactly compatible; but I think many people used none as an "i
don't care" value in which case Default::default() might be more
appropraite

Closes #ISSUE

Release Notes:

- N/A

crates/git_ui/src/commit_view.rs

@@ -1,6 +1,6 @@
 use anyhow::{Context as _, Result};
 use buffer_diff::{BufferDiff, BufferDiffSnapshot};
-use editor::{Editor, EditorEvent, MultiBuffer};
+use editor::{Editor, EditorEvent, MultiBuffer, SelectionEffects};
 use git::repository::{CommitDetails, CommitDiff, CommitSummary, RepoPath};
 use gpui::{
     AnyElement, AnyView, App, AppContext as _, AsyncApp, Context, Entity, EventEmitter,
@@ -154,7 +154,7 @@ impl CommitView {
             });
             editor.update(cx, |editor, cx| {
                 editor.disable_header_for_buffer(metadata_buffer_id.unwrap(), cx);
-                editor.change_selections(None, window, cx, |selections| {
+                editor.change_selections(SelectionEffects::no_scroll(), window, cx, |selections| {
                     selections.select_ranges(vec![0..0]);
                 });
             });