[Bug] Needextend shall only reference needs in same document

### Description

In the next release of Docs-As-Code (after 4.3) we will enable the check regarding needsextend that will validate that the `c.this_doc()` is inside the filterstring.
This means that **only** needs in the same document can be changed / manipulated via needextends.

Currently in the process description this is not the case, many needextends manipulate a lot of different needs not in the same document.
Also the non external filter `is_external == False` should be added too.

### Analysis results

See current needextend usage: https://github.com/search?q=repo%3Aeclipse-score%2Fprocess_description%20needextend&type=code

Many parts already do use c.this_doc() though many still do not.
Also please ensure to have 'is_external == False' is added to them

### Solution

Add `c.this_doc()` as well as `is_external == False` to all needextends and move / copy them where needed to ensure they only manipulate elements in the same document.

### Error Occurrence Rate

None

### How to reproduce

_No response_

### Supporting Information

_No response_

### Classification

Minor

### First Affected Release

not released (main)

### Last Affected Release

not released (main)

### Expected Fixed Release

before release (main)

### Category

- [ ] Safety Relevant
- [ ] Security Relevant