Replace pose in Grid3d with GzPose

[AzulRadio]

Signed-off-by: youhy haoyuan2019@outlook.com

New feature

Summary

As title. The behavior should be exactly the same as before.

Test it

Checklist

• Signed all commits for DCO
• Added tests
• Added example and/or tutorial
• Updated documentation (as needed)
• Updated migration guide (as needed)
• Consider updating Python bindings (if the library has them)
• codecheck passed (See contributing)
• All tests passed (See test coverage)
• While waiting for a review on your PR, please help review another open pull request to support the maintainers

Note to maintainers: Remember to use Squash-Merge and edit the commit message to match the pull request summary while retaining Signed-off-by messages.

[codecov]

Codecov Report

Merging #461 (ca7acf5) into ign-gui3 (8bc5bed) will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff            @@
##           ign-gui3     #461   +/-   ##
=========================================
  Coverage     69.81%   69.81%           
=========================================
  Files            29       29           
  Lines          3273     3273           
=========================================
  Hits           2285     2285           
  Misses          988      988           

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[jennuine]

Let's use the IgnHelpers.getDecimals:

gz-gui/src/plugins/grid_3d/Grid3D.qml

Lines 33 to 41 in 451146b

	// Get number of decimal digits based on a widget's width
	// TODO(chapulina) Move this to a common place so all widgets can use it
	function getDecimals(_width) {
	if (_width <= 80)
	return 2;
	else if (_width <= 100)
	return 4;
	return 6;
	}