Search: bugs and improvements

This is a collection of known bugs/improvements for the new search interface. Feel free to add new items here.

• The initial aggregations saved for checkboxes can be incorrect if the filters are not empty when arriving at the search page (e.g. when navigating back from the entry page.)
• The infinite scrolling is using pagination with increasing page size: this should be changed to use ES search_after functionality.
• Intelligent grouping of aggregation requests. Currently each component requests aggregations separately, these could be grouped somehow into a single API call (at least during initial page load).
• URL-encoding for queries. The query string should reflect the currently selected filters.
• Sorting of the result list by a specific field is currently disabled due to issues in API/quantity name mapping. Should be fixed.
• Introducing a better naming scheme for search-related components.
• Get rid of all old APIv0 calls and the old search code
• Use the selected unit system also in the search bar queries
• Improving the unit behaviour in range queries: show units in filter summary, enable ellipsis in range text fields, make the range, current selection, and step adjust according to the unit system.
• The timestamps shown in the filters should be formatted
• Suggestions only match the beginning of formulas, authors etc. Need a custom tokenizer.
• Refactor FilterTree so that it accepts menu items directly as children.
• More consistent band gap search: combine band gap value and type into one nested query.
• Enable metainfo value "parsing" (utils.parseMeta) in the search bar: this would allow using custom units, parsing special values (e.g. boolean values) etc.
• Suggestions are called unnecessarily often when typing in an InputText field.