Enhancements to Projects file switcher

[AngelaRemolina]

Problem Description

• The file switcher gets slow when it is searching in a big project. This is caused because the subprocess that executes the fzf command waits for the output, so if the output takes a lot of time, the screen could freeze. A posible solution for this is to migrate this from a subprocess to a ProcessWorker.
• Another styling detail is that the switcher highlights in bold the search text that is matching the item title. But this only occurs in when it's searching for an open file, but when it's searching inside the project files it does not highlight the matching characters (look at the gif below)