docs: move Controller recipes to how-to guides

[bajtos]

At the moment, the Controllers page in "Behind the scenes" is mixing explanations with how-to guides. This makes it difficult for our users to find the relevant content (a recipe to achieve the outcome they want).

As part of our adoption of the four-quadrant documentation system (see #5549 and #5718), we should extract all guides from explanation pages into guide pages (see #5768 for inspiration) and keep explanation pages focused on explaining the concepts & providing background information.

This story is a part of Epic #5783 move recipes to how-to guides.

Acceptance criteria

Move the following recipes into "How-to guides", decide yourself whether to create a new page for each recipe or group multiple recipes in one page.

• How to allow parameterized decorations
• How to define controller classes at runtime
• How to report a custom error from a controller method

Consider adding a "Common tasks" section to "Application" page, it should list pointers to new how-to guides. See Server >> Common tasks for inspiration.

[mrmodise]

Will take this on. Thanks JannyHou took it over

[mrmodise]

@jannyHou if you don't I can take this on?

[jannyHou]

Hi @mrmodise I was on vacation :p I have some other tasks to work on, please feel free to take this task, appreciate it.