Fix reentrency issues with magic search :

• store search parameters into Core.
• add search limitation to avoid 300 useless items.
• retrieve old parameters on proxy when changing list.
• store parent proxy to avoid MOC warnings.

Fix contacts search views:

• add a loading state for buzy indicators.
• limit results on suggestions.
• avoid to create MagicSearchProxy if not needed.
• add a status to know if friend is stored or not.
• propagate invalidateFilter.
• delay search while typing.