add EOF as second delimiter along with ;

Summary

This MR covers 3 issues (#1059 (closed), #1065 (closed), #1067 (closed))

1. #1059 (closed) - EOF is added as a second delimiter, but only processed when reading the files (last line of the file can be without a delimiter ;)

2. #1065 (closed) - Special commands can be executed with and without specifying delimiter ;

3. #1067 (closed) - Additional console prefix(prompt) added '>'. It is shows when input is waiting for delimiter (See example)

4. New special command \set delimiter enter to change delimiter to EOL (end of line - enter)

• Close #1059 (closed), #1065 (closed), #1067 (closed)

• Cherry-pick to: 24.6

• Docs follow-up: docs#403 (closed)

• Follow-up for !1363 (merged)

Closes #1059 (closed), #1065 (closed), #1067 (closed)