[import] import multiple files in a directory in one step

Description

Import directories - import multiple files in a directory in one single step

Additionally to the already existing "Import from File" functionality we introduce the ability "Import from Folder". Upon the selection of the folder, all files in this folder are imported into the project in one step.

Details and limitations of the current implementation:

• We import into Spreadsheets only for now. The support for the import into Matrix can be added later, if needed.
• We create new spreadsheets for every file with the name of the file and import in the replace mode. If the spreadsheet with the proper name (from a previous import, etc.) is already existing, we use this spreadsheet and replace the old data with the new data.
• We import the files in the directory only, the sub-directories are not traversed
• We assume all files in the selected directory have the same format and data structure. If this is not the case, the imported data will be wrong and it's the responsibility of the user to use this feature properly.

Screenshots:

New entry in the main menu:

Directory selection in the Import Dialog with the preview of the first file in the directory:

Two spreadsheets for the two files in the directory created after the import

Create a new workbook from within the import dialog to import into it:

Two spreadsheets created in the workbook after the import:

Information about the directory to be imported:

Conformity

• Changelog entry
• Unit tests
• Update INSTALL
• Downport
• Fixes: