fix MacOS keystore

[kernelkind]

MacOS keystore impl is behaving strangely. In some cases, when opening the app it is asking for the MacOS user password for every entry in the keystore even after selecting "always allow".

It should only ask for password once per account added when "always allow" is selected, and then never again. If this isn't possible in security-framework, a basic file storage impl should be used instead, or possibly try #138 .

will close #137