Improved shortcuts fidelity and tool groups to Photoshop's behavior

[pierspad]

Since GIMP currently lacks the ability to cycle through grouped tools by repeatedly pressing the same hotkey (I talked with the dev team and they will looking into this behaviour to see if it's worth implementing, but for now we have to adapt), with this PR I propose a "modifier-based" approach (<Shift> and <Shift><Alt>) as a "best-effort" alternative.

If the group cycling shortcut will eventually be implemented it would also be easier to change all the shortcut simply by removing the modifiers for each group

Example with the "O-Group"

Tool	Mod 1	Mod 2	Key
Dodge/Burn:	--	--	O
Blur/Sharpen:	--	Shift	O
Smudge:	Shift	Alt	O

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Changes

• Fixed Path Tool Shortcut: Replaced the non-functional tools-vector entry with the correct action name tools-path.
• Deduplication: Removed a duplicate entry for tools-rect-select in the configuration.
• Smart Selection Regrouping: Moved tools-foreground-select out of the manual selection group (Free Selection/Scissors Selection) and into the "smart" selection group alongside fuzzy-select and by-color-select.
• Clone/Healing Separation: Moved the Healing Brush into its own separate logic/category instead of leaving it under Clone Stamp, matching the standalone Photoshop workflow.

Summary

(note that some were already present and were just made explicit in the file)

Tool	New Shortcut
tools-path	p
tools-gradient	g
tools-text	t
quick-mask-toggle	q
tools-zoom	z
tools-eraser	e
tools-rotate	<Shift>r
tools-measure	<Shift>i
tools-iscissors	<Shift>l
tools-pencil	<Shift>b
tools-by-color-select	<Shift>w
tools-foreground-select	<Shift><Alt>w
tools-transform-3d	<Shift><Alt>t
tools-convolve	<Shift>o
tools-smudge	<Shift><Alt>o
tools-perspective-clone	<Shift>s
tools-align	<Shift>v