Sidepanel submodule improvements

[gerhardol]

Closes #8714
Second part of #8703
Based on #8703 that is set to automerge so not to be merged yet. Fully reviewable.

Best reviewed commit by commit

Proposed changes

• Open submodule in left panel selects first/selected commit as in Submodule browse: Select both first/second commits #8703
• Add actions in Commit/RevDiff worktree to submodules: Reset/Stash/Commit
• Add Open in new instance for submodules
• Tooltip with details for changed submodules. This adds extra git-diff for modules that are dirty only (for others the command were executed anyway). The number of changes reported are limited to five changes (similar to how the RevGrid tooltip is limited already)
• For topmodule there is no submodule status message available, display the same tooltip as for the RevGrid WorkTree commit.
• A few minor refactorings were required

Review commit by commit.
Several of the changes will be squashed at approval.

Screenshots

Using a testrepo with GE modules recursively added (originally to test performance)

Before	After
(all submodules do not have tooltips)
Commits selected when opening a submodule from left panel

Test methodology

Manual
Mostly UI changes, using already existing

---

✒️ I contribute this code under The Developer Certificate of Origin.

[codecov]

Codecov Report

Merging #8726 (b38b46b) into master (668dafe) will decrease coverage by 0.05%.
The diff coverage is 31.97%.

@@            Coverage Diff             @@
##           master    #8726      +/-   ##
==========================================
- Coverage   56.05%   56.00%   -0.06%     
==========================================
  Files         902      903       +1     
  Lines       65134    65184      +50     
  Branches    11825    11844      +19     
==========================================
- Hits        36513    36507       -6     
- Misses      25702    25744      +42     
- Partials     2919     2933      +14     

Flag	Coverage Δ
production	43.12% <31.97%> (-0.06%)	⬇️
tests	94.80% <ø> (-0.02%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

[ghost]

var ending = string.Empty;

if (items.Count > 1)
{
    ending = "s";
}

builder.AppendFormat("{0} {1}{2}", items.Count, singular, ending)
    .AppendLine();

[gerhardol]

If this is to be changed interpolated string should be used instead

                builder.Append($"{items.Count} {singular}{(items.Count == 1 ? "" : "s")}")
                    .AppendLine();

[ghost]

A new string object will be created every time.

[ghost]

[gerhardol]

Rebased on master and removed draft, added review comments

[RussKie]

I checked out 4ba1413 but the submodule status didn't seem to work for me:

The context menu worked though:

[gerhardol]

I checked out 4ba1413 but the submodule status didn't seem to work for me:

Did you deactivate when we had performance problems a couple of years ago?

[gerhardol]

Rebased after #8734, review comments

[RussKie]

Did you deactivate when we had performance problems a couple of years ago?

Of course I did :)

I'm going to turn it on, and try again

[gerhardol]

Still valid, #8738 fixed #8726 (comment)

[gerhardol]

I'm going to turn it on, and try again

Any opinions?

I find that the tooltip to get the status is something I really missed, I do not have to open the submodules to see expected changes only (like dirty files).

[RussKie]

I'm going to turn it on, and try again

Any opinions?

Yes, that worked :)

[mstv]

Since I use submodules rarely, I cannot say much. I will review formally in the next days.

Should the two Open context menu items have more specific texts? Or do the different icons and tooltips suffice?

English.xlf needs an update (tooltips).

I guess #8703 was meant instead of #8700 in the PR description.

[gerhardol]

Should the two Open context menu items have more specific texts? Or do the different icons and tooltips suffice?

The new instance could be called "Open with Git Extensions" as it is called in other menus, but I do not believe that is clearer.
Open in the current GE instance is a special case. This is how open of branches in the sidepanel works, so use the same instance is expected when double clicking.

[RussKie]

Why?