Fix for Knife-ec2 server list doesn't show instance name

[kapilchouhan99]

Description

• Now Knife-ec2 server list show instance name
• Added test cases
• Ensured chefstyle on the code changes made

Output

msys@PUN-LAP-KAPIL-C:~/workspace/knife-ec2$ bundle exec knife ec2 server list --region us-east-2 -c /home/msys/workspace/assignment_2/.chef/knife.rb
Instance ID          Name                         Public IP       Private IP     Flavor      Image                  SSH Key                   Security Groups                                                                      State
i-0859dc3ef6c652565  kchouhan-red-8                               IP_ADDRESS   t2.micro    ami-03d64741867e7bb94  kchouhan                  launch-wizard-85                                                                     stopped
i-0b3fc2e3d524394b3  kchouhan-windows             IP_ADDRESS      IP_ADDRESS  t2.micro    ami-00133f78ad56a5c91  kchouhan                  launch-wizard-63                                                                     running
i-0132edf11f3d63b21  kchouhan-7.8                                 IP_ADDRESS  t2.large    ami-08de027b0238b586e  kchouhan                  Red Hat Enterprise Linux Server 7-8 -Maipo--RHEL-7-8-20200506-10GiB-AutogenByAWSMP-  stopped

Related Issue

Fixes: #662

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Chore (non-breaking change that does not add functionality or fix an issue)

Checklist:

• I have read the CONTRIBUTING document.
• I have run the pre-merge tests locally and they pass.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.
• All commits have been signed-off for the Developer Certificate of Origin.