Plan: Simple editor conversion to FactTextFieldSlider

[DonLakeFlyer]

• Finish converting simple item (waypoints, ...) editor to FactTextFieldSlider usage
• Add enable check box support to FactTextFieldSlider
• Update metadata adding values for userMin/Max

[Copilot]

Pull request overview

This PR refactors the Simple Item Editor to use the FactTextFieldSlider component throughout, replacing the previous GridLayout with individual FactTextField controls. The PR adds enable/disable checkbox support to FactTextFieldSlider to handle optional parameters (nanFacts) and optional flight speed settings.

Key Changes:

• Replaces GridLayout with individual Repeaters and FactTextFieldSlider components for a more consistent and maintainable UI structure
• Adds optional checkbox functionality to FactTextFieldSlider for enabling/disabling parameter fields
• Enriches metadata with userMin/userMax ranges to enable slider controls for various mission parameters

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
src/QmlControls/SimpleItemEditor.qml	Refactors from GridLayout to individual Repeaters using FactTextFieldSlider, adds visual separators, implements checkbox pattern for nanFacts and speedSection
src/FactSystem/FactControls/FactTextFieldSlider.qml	Adds showEnableCheckbox property, enableCheckBoxChecked alias, and enableCheckboxClicked signal; wraps LabelledFactTextField in RowLayout with optional checkbox
src/QmlControls/QGCSlider.qml	Adds QGCPalette instance for proper color theming support
src/MissionManager/SpeedSection.FactMetaData.json	Adds userMin (0) and userMax (30) for FlightSpeed to enable slider functionality
src/MissionManager/MavCmdInfoCommon.json	Adds userMin/userMax metadata for multiple MAVLink command parameters, fixes decimalPlaces for yaw parameters, adds param7 definition for MAV_CMD_CONDITION_CHANGE_ALT