Add new "Saved addresses" window and Debug CPU option to show that window

[rpcs2]

The Memory Observer window allows users to search, scan and find addresses of patterns and values in memory but once the addresses are found the only 3 options to what to do with each found addresses are: Go to in Memory Editor, Add Read Breakpoint and Add Write Breakpoint.

I would like to have fourth option: Add to saved addresses

This is a button that adds the address to the saved addresses list that the "Saved addresses" window displays when visible.

With this feature the user no longer needs to create new text file and write down in it the found addresses that he/she wants to explore/investigate/inspect/follow later.

Optional Bonus (Extra):

In the "Saved addresses" window add "Edit" button and "Freeze" checkbox for each address that appears in this window.

The "Edit" button allows to change the value of an address and the "Freeze" checkbox allows to freeze the address like how it is already done in the Memory Observer window Delta-over-time search tab.

Additionally add "Add address manually" button at the bottom of that window that allows it's users to add any address to that list manually.