Provide sensible defaults to interactive prompts

Also fix the error on Create Databases [y/n] prompt because of recent
updates.

Signed-off-by: Vivek Rai <vivekraiiitkgp@gmail.com>
Suggest proper/processed names when creating dbs.

Signed-off-by: Vivek Rai <vivekraiiitkgp@gmail.com>
Move db dir prompt message into readline

Signed-off-by: Vivek Rai <vivekraiiitkgp@gmail.com>