[FIX] Search: Fixed the display of a false report and the error on an empty string search.

Task link: https://avan.tech/item19311

After analysis, I found that the displayed alert was not a false report. This is because the default value of the search_date_facets_ranges pref is changed when performing the search. In fact, this value is not modified as such, it's just that the default string contains the "\n" character at the beginning, while this character is removed when defining date facet ranges. Hence the display of the alert since the string has changed. So to fix the problem I had to change the default value of the preference by removing the "\n" character.

While working I found another bug as reported here. For this case, I noticed that this error was due to the fact that after performing a search, when displaying the result, a query was prepared for displaying the occurrences when clicked on a given column of the result. So during the next search if the search string is not provided, this creates confusion on the request to be processed. To solve the problem, I had to make sure that when we launch a search, the query prepared for the display of occurrences is canceled.