Quality of life fixes

[fredrikkarlsson-pervanovo]

This fixes some of features that I think are missing in Lokalize, which I love and use. Here are the features and my comments on why they are quality of life fixes.

Remember last changed multiline

Most of my translations are one-liners and it would be nice to remember the last type so I can add many one-liners without having to change the multiline each time.

Autofocus key input

When adding a key it is quite probable that one wants to enter a key directly.

Clear filter

When filtering keys it is nice to be able to clear the filter without ctrl-a and delete, I have implemented clicking the filter icon and esc key up when in field.

Newly added keys on top

I usually lose track of my newly added keys and have to filter for them. It is easier if they are placed first when added.

[fredrikkarlsson-pervanovo]

@aheinze Quite straight forward or what do you think? I have separated the different features into different PR's if you dont want them all.

[fredrikkarlsson-pervanovo]

Rebased my PR branches on the updated code