Fix missing attributes in FormBuilder inputs

[bennothommo]

Commit 2ef3234 made some adjustments to the input method arguments that resulted in the some attributes not being populated if the name of the input was not provided. This commit changes the structure of the condition so that these attributes are properly filled in.

I've also redone the tests using some custom assertions so that the order of the attributes does not matter when testing. The previous tests were a bit flimsy in this regard.

Fixes wintercms/winter#864

[what-the-diff]

PR Summary

• Added null coalescing operator to FormBuilder::token()
  Improves code readability and handles null values in a more efficient way.

• Changed type of $session to allow for nullable types
  Allows for more flexibility in the session handling within the FormBuilder.

• Removed unused use statement and added Request facade import
  Streamlines dependencies and fixes the import for better code organization.

• Created AssertHtml trait for easier HTML testing
  Provides new assertions for testing HTML output, improving testing capabilities.

• Added and improved various tests for FormBuilder
  Enhances test coverage for the FormBuilder, ensuring better functionality and reliability.

• Fixed ID attribute issue with inputs and labels
  Resolves a problem where the ID attribute was inconsistently set, improving form accessibility and structure.

• Created submit() and button() methods in FormBuilder
  Adds missing functionality to FormBuilder, enabling its usage in other systems like OctoberCMS, and achieving parity between frameworks.

[mjauvin]

Great work on the AssertHtml trait @bennothommo!

Just a few things I noticed in the new test cases.

[bennothommo]

Thanks for reviewing @mjauvin :)

[mjauvin]

Looks good to me, with all those amazing tests!