Export import connections

[squashi6]

Description

Include a summary of the change.

Fixes #65

Type of change

Please delete options that are not relevant.

• Bug Fix (non-breaking change to fix a bug)
• New Feature (non-breaking change to add a feature)
• User Configuration Change (change that requires migration of local user configuration)
• Plugin API Addition (non-breaking additional feature to communicate with plugins)
• Plugin API Change (breaking change the plugin API, which makes existing plugins incompatible)

How to test

Please describe steps to test your change.

• In the edit Connections View there are two new icons in the bottom of the Connection List. The first is to export Connections. By clicking a new Dialog opens. The dialog includes a list of all existing connections. The user can select the connections to be exported. By clicking the Export button a file choser opens and the connections are stored in a json file. The user can chose a password to encrypt the connections. If the user does not use a password, all passwords are deleted from the export.
  The second new button opens a file chooser to select a json file. By selecting a valid json file including exported connections, a new dialog opens. If the connections are not encrypted, a list with connections is showed. The user can select connections and import them by pressing the import button. If the connections are encrypted, a password field is shown. By entering the correct passowrd, a list of connections is displayed. By clicking import, the selected connections are imported.
• Do Y

Requirments:

• Plugins:
• Specific broker:

Checklist:

• Code follows the coding guidelines
• Code is understandable by others
• Code is commented
• Migration of local user data is included (if relevant)
• No unexpected warnings or exceptions are thrown.
• Plugin compatibility is checked (if relevant)
• Unit Tests are added