Adding the option for specify the project title on packaged project

[SeqLaz]

This adds the option to specify a new project name and title in the exported project when packaging.

Before	After

Related PR: opengisch/libqfieldsync#94

[suricactus]

Instead of complicating the code in the caller (in this case QFieldSync), we should add this functionality within the OfflineConverter itself. Why? Because the converter already does the copy of the file.

For example here we have hardcoded the name of the output file: https://github.com/opengisch/libqfieldsync/blob/master/libqfieldsync/offline_converter.py#L276

What we can do is to pass the output name to be a parameter when we construct the OfflineConverter class. We can even replace the export_dir param with export_filename param, and then derive the export_dir to be the path to export_filename.

[suricactus]

Please note that most of the suggestion here need code-wide changes, the suggestions are only pointing to the highlights.

[SeqLaz]

Please note that most of the suggestion here need code-wide changes, the suggestions are only pointing to the highlights.

@suricactus The changes and suggestions were addressed in this PR

[suricactus]

Few comments after the libqfieldsync review:

• Drop the "export directory" and export finame in favor of single "export filename" with the full path
• After clicking "Create" OR when changing the value of "export filename", make sure the user is notified there is already a file with that name in that location.
• Prepopulate the "export_filename" with the default value of "export directory" with "/" and current project basename and "_qfield" suffix and ".qgs" extension. You can create a utility function in libqfieldsync get_export_filename_suggestion(project.fileName())

Please update the screenshot when ready.

[suricactus]

Not there yet.

[SeqLaz]

Not there yet.

Hey @suricactus please have a look.
I squashed due to the PR had a lot of merge. In the last commit I addressed all the suggestion and some improvements.

[SeqLaz]

Hey @suricactus, I added a message box that informs the user they should use the .qgs extension. Have a look!

[SeqLaz]

Hey @suricactus I added the typing hints on the new functions I added, have a look!

[SeqLaz]

Hey @suricactus, I deleted the unnecessary function and joined the functions of export_folder and get_filename_suggestion.