fix(cpn): save lastDir when opening a file

[pagrey]

Fixes #5157 and fixes #4813

Summary of changes:
Ignores updateLastUsedDir boolean and updates the last directory used.

I don't know the purpose of not saving the last used directory and I don't know the impact of removing all the code associated with removing this boolean value so I set it true so the directory is updated. Companion hasn't updated the directory location in seven years but these two issues reference the problem and this is a very simple fix.

[elecpower]

My personal preference is to update the last used directory on save as this would normally be where you store the majority of your files whereas opening files could be from more varied locations such as main storage location, backups, usb drives, downloads, emails, etc.