ts_client: Create SW component requirements and establish traceability

[lavrovvalera]

Important

Link the implementing PR to this issue by including Closes #75 in the PR description or commit message.

What

Write the component requirements document for score/ts_client.

score/ts_client has production code (gPTP IPC publisher/receiver) and active
development (PR #54 replacing mmap with SharedMemoryFactory) but no component
requirements. Requirements shall be authored as comp_req sphinx-needs directives
at score/ts_client/docs/requirements/ts_client_requirements.rst, traced to
feature requirements via :satisfies: feat_req__time__<id>, and back-linked to
code via // # req-Id: comments.

Acceptance Criteria

• score/ts_client/docs/requirements/ts_client_requirements.rst created and indexed
• All significant observable behaviours covered as comp_req nodes (connect/disconnect, publish, receive, error paths)
• Every comp_req has a :satisfies: link to a valid feat_req
• Every comp_req traced to code via // # req-Id:

References

• S-CORE Requirements Engineering