Refactor CMSIS View

[ReinhardKeil]

Improve the structure of the CMSIS View

[edriouk]

The central idea of the refactoring is to replace SolutionNode type in SolutionOutlineTree with CTreeItem class.

Advantages:

• CTreeItem represents a generic tree with label, attributes and child elements
• new attributes can be introduced without modifying the type
• can be written to a YAML string that can ease testing: compare result with golden reference

An estimated effort is ~2 weeks including adding tests for the existing Outline View content functionality

[edriouk]

Create a new class COutlineItem that extends CTreeItem (later we can decide to derive it directly from GenericTreeItem.
Some methods need to be overwritten to return COutlineItem, in particular createItem(), getChildItem(), getParentItem()

Please note that:

• CTreeItem does not have defined properties, but uses methods to access them.
• there is no need to define and add additional data structures like data in solutionNode

COutlineItem should use the following rules to store information:

1. Use tag property as a tree item label (constructor, getTag(), setTag())
   const cprojectItem = new COutlineItem(projectName);

2. Let parent nodes create their children:
   const groupItem=cprojectItem.createChild(groupName);

3. Use setAttribute()/getAttribute() to insert additional information for instance:
   groupItem.setAttribute('icon', 'csolution-files');
   Item need to store only relevant attributes which are non-empty.
   For instance, if an item has an associated document, use: item.setAttribute('doc', url);
   of for an associated header file: item.setAttribute('header', headerName);
   Since attributes can only be string, use 'none', 'expanded, 'collapsed' strings, e.g.
   item.setAttribute('expandable', 'none'); or item.setAttribute('expandable', 'expanded');

4. Item context should be obtained over a special method COutlineItem.getContext() string | undefined
   the returned string should a set of available contexts for the item separated by semicolon, e.g: 'hasDoc;hasHeader'
   Regular expressions in package.json then can match sub-stings or their combinations

5. To test the tree: write it to a YAML string using CTreeItemYamlParser or corresponding toYamlString() global function
   then match the string against golden reference stored as a YAML file, matching needs to escape absolute paths

Later it could make sense to accommodate additional functionality in COutlineItem, in particular:

• provide specific virtual methods
• store reference to the original CTreeItem read from YAML file: this can ease editing