docs(cli): correct the relationship path form and note the TOM name

[MariaJoseFF]

Closes work item 7269.

Targets user-pg/cli-0.7.0 (the branch behind #386), not main - these are 0.7.0 docs and must not go live before the CLI ships.

The problem

The Containers and keywords section documented relationship paths as Relationships/{guid}. As of 0.7.0, { and } are reserved characters in CLI object and filter paths ([Breaking] Braces asterisks and question marks in object names must be quoted in paths), so that form is refused by the path parser rather than resolved:

te get "Relationships/{2c4f8a19-1c2d-4e3f-9a8b-7c6d5e4f3a2b}"
Error: '{' at position 14 is reserved for future brace expansion.
       Quote the segment to use it literally: '{foo}' or "{foo}".
exit 1

The single-quoted form is refused too, because a single-quoted segment must reference a table. Double quotes and brackets both resolve.

Two rules in the same release contradicted each other.

The change

One paragraph in content/features/te-cli/te-cli-commands.md:

• Relationships/{guid} -> Relationships/"{guid}"
• Adds a note that --paths-only prints the relationship's TOM name, which is not always a GUID: the GUID in Power BI models, a display-style name such as Relationships/Relationship 1 in SSAS-sourced models.
• Explains why the quoting is there, so the path form and the reserved-character rule no longer read as contradictory.