Generate equidistant Date&Time and integer values in the spreadsheet

Description

This MR implements the generation of equidistant DateTime values ("time series") and integer values in the spreadsheet which was possible for double values only in the past. The dialog allows to generate numeric and datetime values at the same time (numeric and datetime columns were selected in the spreadsheet and the "generate equidistant values"-dialog was called):

In case only numeric columns or only datetime columns were selected, the relevant part only is shown:

With this MR it's also possible now to generate values by fixing the number of them and the increment at the same time (either fixing the number of fixing the increment was possible in the past). This allows to generate data range like "generate 100 values starting from 0 and increasing by 5" or "generate 20 datetime values starting from today and increasing by 1 day", etc:

with the result

Furthermore, we properly handle the conversion of the column modes when needed. For example, "generate equidistant values" was called for an integer column but the increment is a float number and the column needs to be converted to "Double", or the integer values go beyond the max int value and the column mode needs to be changed to "Big Int".

Conformity

• Changelog entry
• Unit tests
• Update INSTALL
• Downport
• Fixes: #564 (closed)

When external dependencies are removed

• Reporting to ...