Field plugins

[Sutharsan]

Add the following commands:

generate:plugin:field              Generate field type, widget and formatter plugins.
generate:plugin:fieldformatter     Generate field formatter plugin.
generate:plugin:fieldtype          Generate field type plugin.
generate:plugin:fieldwidget        Generate field widget plugin.

Have not added a config/dist/chain.yml file yet. Not sure if it is needed.
Needs more testing.

Nice to have: smart defaults for formatter and widget names, suggestions for field_types.

[jmolivas]

@Sutharsan: Thanks for the PR, I will be testing it later on today.

[jmolivas]

@Sutharsan:

• Have not added a config/dist/chain.yml file yet. Not sure if it is needed.
  We added to make sure travis test the generated code
  https://github.com/hechoendrupal/DrupalConsole/blob/master/.travis.yml#L35
  https://github.com/hechoendrupal/DrupalConsole/blob/master/.travis.yml#L36
• Needs more testing.
  Few changes need related to coding standards here but since I am testing a new project to analyze code I will merge this and take as an opportunity to test this tool.
• Nice to have: smart defaults for formatter and widget names, suggestions for field_types.
  You can define defaults for commands I need to add that to the docs.
  This feature was added by PR Set defaults for commands #731
  If for defaults you mean autocomplete predefined values, then take a look at this Trait and search for $input_types
  https://github.com/hechoendrupal/DrupalConsole/blob/master/src/Command/Helper/FormTrait.php#L29
  https://github.com/hechoendrupal/DrupalConsole/blob/master/src/Command/Helper/FormTrait.php#L74
  https://github.com/hechoendrupal/DrupalConsole/blob/master/src/Command/Helper/FormTrait.php#L88