Styles need a way to set the default icon color for controls. Until
now, that was done like this:

    icon.color: "tomato"

    contentItem: IconLabel {
        icon: control.icon
    }

This breaks the use case of e.g. an Action that sets its own
icon.color, because the icon property of the control always takes
precedence (see 146bc9517c56feda4eba34282d3cc53bd47b6267).

This patch adds a defaultIconColor property to IconLabel, which allows
styles to specify a color without overriding any potential action's
icon:

    contentItem: IconLabel {
        icon: control.icon
        defaultIconColor: "tomato
    }

If icon.color was explicitly set, it is used instead.

This does mean that overriding the contentItem will result in the
icon color being lost, but that is already the case for style
customizations in general.

All controls that set icon.color and using IconLabel to display their
icon are affected and are therefore adapted: Button, CheckDelegate,
DelayButton, ItemDelegate, MenuBarItem, MenuItem, RadioDelegate,
RoundButton, SwipeDelegate, SwitchDelegate, TabButton, ToolButton.

Add FlowPane to the shared folder of the baseline test and use it in
the tests that we touch. This fixes two issues:
- Using Pane as the background fixes text being invisible for some
styles.
- Using Flow provides the most space-efficient layouting of items now
that we have more than would fit in the old layout.

Task-number: QTBUG-87459
Change-Id: I455ce7202a46b7cfa7545650574e48ad72796675
Reviewed-by: Oliver Eftevaag <oliver.eftevaag@qt.io>

The files (folders) already processed are listed in each issue in epic
QTBUG-134547

These files were processed half a year ago. In order to make it clear
that all of these files are already processed, mark them with an
explicit default security header.

For the record, this was generated with this script:

find -E . -regex ".*\.(cpp|h|hpp|mm|qml|js)$" | xargs python3 ~/bin/add-cra-header.py

in the folders listed in each subtask of QTBUG-134547

(add-cra-header.py only exist at my desktop, but it simply adds the
default security header if it doesn't already have any existing security
header)

QUIP: 23
Fixes: QTBUG-134547
Pick-to: 6.10 6.9 6.8
Change-Id: Ieb8c78ea6561fdbdd27c7b13185ece853eedf80f
Reviewed-by: Oliver Eftevaag <oliver.eftevaag@qt.io>

Qt Quick Controls 2 was named that way because it was a follow-up to
Qt Quick Controls 1.x. Now that Qt Quick Controls 1 is no longer
supported, we don't need to have "2" in the name. Work on this was
already started for the documentation in
1abdfe5d5a052f2298b7bf657513dfa7e0c66a56.

By doing this renaming a few weeks before feature freeze, it won't
affect the release but still results in as little time possible spent
manually fixing conflicts in cherry-picks from non-LTS releases as a
result of the renaming.

This patch does the following:

- Renames directories.
- Adapts CMakeLists.txt and other files to account for the new paths.

A follow-up patch will handle documentation.

It does not touch library names or other user-facing stuff, as that
will have to be done in Qt 7.

Task-number: QTBUG-95413
Change-Id: I170d8db19033ee71e495ff0c5c1a517a41ed7634
Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>