new V5 section for architecture requirements

[elarlang]

Title

Proposed title by @tghosth : Validation and Sanitization Architecture

Preferred title by @elarlang (to re-use current 1.5): Input and Output (processing?) Architecture

Chapter text

With syntax-specific requirements we say "do the correct thing" and here are the requirements to say "do it in correct order" and in "correct place".

<!--
The requirement belongs here if it is:

  * input validation, sanitization or encoding architecture
  * input validation, sanitization or encoding processing (order)

The requirement does not belong here, if it is:

  * syntax specific or clear input validation, sanitization or encoding requirement

reorg: move it to 1st chapter in the paragraph
-->

Requirements

At the moment is the plan to create or move to this section:

• 5.1.6 needs added clarity #1553
• 5.3.11 is not practically testable #1484
• proposal: new separate requirement - decode should be done only once and before processing input data #1590

[tghosth]

Apologies but I don't think "Input and Output (processing?) Architecture" is a good heading, I would prefer my original proposal.

@elarlang can you open a PR for this.

[elarlang]

@elarlang can you open a PR for this.

At the moment I think I'll do it when I have agreements in related issues.