[7.x] Check route:list --columns option case insensitively

[matt-allan]

The route:list command has a --columns option you can use to specify what columns should be used. Weirdly if you use the same case for the column names the output uses nothing at all gets printed:

 $ php artisan route:list --columns 'Method,Uri'

It only works if you use all lowercase:

$ php artisan route:list --columns 'method,uri'
+----------+------------------------+
| Method   | URI                    |
+----------+------------------------+
| GET|HEAD | /                      |
| GET|HEAD | api/user               |
| GET|HEAD | home                   |
| GET|HEAD | login                  |
| POST     | login                  |
| POST     | logout                 |
| GET|HEAD | password/confirm       |
| POST     | password/confirm       |
| POST     | password/email         |
| GET|HEAD | password/reset         |
| POST     | password/reset         |
| GET|HEAD | password/reset/{token} |
| GET|HEAD | register               |
| POST     | register               |

This PR changes the comparison to be case-insensitive so you can use the same case as the output, lowercase, all uppercase, etc and it still works:

 $ php artisan route:list --columns 'Method,URI,name'  
+----------+------------------------+------------------+
| Method   | URI                    | Name             |
+----------+------------------------+------------------+
| GET|HEAD | /                      |                  |
| GET|HEAD | api/user               |                  |
| GET|HEAD | home                   | home             |
| GET|HEAD | login                  | login            |
| POST     | login                  |                  |
| POST     | logout                 | logout           |
| GET|HEAD | password/confirm       | password.confirm |
| POST     | password/confirm       |                  |
| POST     | password/email         | password.email   |
| GET|HEAD | password/reset         | password.request |
| POST     | password/reset         | password.update  |
| GET|HEAD | password/reset/{token} | password.reset   |
| GET|HEAD | register               | register         |
| POST     | register               |                  |
+----------+------------------------+------------------+