Collective-collectionfilter

Breaking Change:

- Add idx parameter to display_modifier call, so that we can use the index name to resolve the correct translated taxonomy titles in collective.taxonomy. This means that the display_modifier method in the groupby_modifier adapters needs to expect this parameter too!
[MrTango]

Bug Fixes:

- Ensure a `GroupByCriteria`'s `sort_key_function` function `lower()` call gets a string.
[jensens]
- Fixed searches for only non-alphanumeric characters causing an exception to be displayed.
[JeffersonBledsoe]

Other:

- Code-Style Black and Isort
[jensens]

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- Updated de and ch-de translations
[agitator]

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- Use collection from context as default. `target_collection` is now used to select an alternative collection as result source.
This allows to copy and paste preconfigured collections for reuse without reconfiguring each filter element.
[agitator]

- Fix search which include the terms "and", "or" and "not"
[jeffersonbledsoe]

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- Do not render filter tiles when page gets AJAX loaded
[petschki]
- Do not add hidden field ``collectionfilter`` multiple times. Fixes 116
[petschki]

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- Separated translation display_modifier for portal_type and Type.
[iham]

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Features:

- Add sorting tile/portlet to populate selected sort indexes to enduser
[petschki]
- Added translation display_modifier for portal_type and Type.
[iham]

Bug fixes:

- fix ``filter_type`` for indexes without ``operator`` capability. Fixes 74
[petschki]