add uppercase shortcut for navigation

[outscale-mal]

🚀 Added / Fixed :

-> Shortcuts to navigate into :

• Create with C
• Volumes with V
• Images with M
• Instances with I
• Security with S
• Nets with T
• Keypairs with K

-> Fix VPC bug when CIDR is missing by adding error handling

-> Code scanning errors :

• Unused imports & local variables
• First parameter of a method is not named 'self'
• Cyclic imports

-> Refactoring

🚩 Problems :

• The letter N can't be used as a shortcut, maybe used somewhere already

[outscale-mal]

Suggestion: I can reorganize the code for shortcuts to put them in a separate file and make the code less heavy in this file :)