BHV-8206: 2.5.0-pre.1 grab-bag fixes

Issue
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When testing 2.5.0-pre.1 against on-device apps, there were a few issues to be addressed:
- Invalid references to the deprecated `enyo.GridFlyWeightRepeater`
- Accessing of an internal `drawers` array that may or may not be initialized
- Drawer mouse events are blocked
- A `moon.Image` kind will always stretch to the size of its container

Fix
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- Remove `moon.GridFlyWeightRepeater`
- Protect against non-existent `drawers` property with guard code
- Modify the `pointer-event` rule value for `moon.Drawers`
- Modify the styling for `moon.Image` such that it will only stretch to the full size of its containers when it has the `sized` class

Notes
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This PR is also related to https://github.com/enyojs/layout/pull/94

Thank you @sbcho for your commits. :)

Enyo-DCO-1.1-Signed-off-by: Aaron Tam <aaron.tam@lge.com>