v1.0.0 release GUI polish

• Correct use of plural and singular form of results/result in the GUI.
• When pressing "show more" and not finding any new values, a simple visual indicator should be displayed, e.g. a disabled button with a tooltip.
• When clearing filters with the button, empty containers (=empty sets) should be considered as a filter that has not been set. Otherwise, the clear button performs a query even if no filters are specified.
• Sections should not be suggested in the search bar, trying to set a value for a section from the search bar should raise an error
• Suggestions list should be cleared whenever the input field is cleared.
• The periodic table statistics are not being correctly updated when the periodic table is "anchored" in the statistics grid.
• Opening the EELS panel in materials search produces a 500 HTTP error.