Add default value for wildfly, format and rework RegexPattern

[The-Huginn]

Resolves #114 and resolves a bug found by @petrberan , when only RegexPattern.enabled property is set to true and RegexPattern.message then results in null.

[The-Huginn]

Please review @petrberan @xstefank

[petrberan]

@The-Huginn What is the behavior when the config is

wildfly:
  format:
    title:

?

[The-Huginn]

Thanks @petrberan . I have added 4 more tests. 2 are testing the suggested correct behaviors from your review and 2 more for the emptry title entry

[The-Huginn]

Also I can add tests for empty commit and description entries, as I have updated them too.

[petrberan]

Please do @The-Huginn