feat: replace work item relations with dedicated dependency and custom relation tools (#148)

* feat: add custom relation and dependency tools for work items

* refactor: remove unused relation removal classes from work item tools.

* chore: enhance work item relation definition retrieval with pagination support

* docs: clarify usage of work item dependency and relation tools.

* chore: merge work item relation tools and definition.

* refactor: streamline initiative handling and enhance server instructions

* feat: add configurable logging for user info (PII) in logs

* chore: flatten logs

* chore: update plane-sdk dependency to version 0.2.17

* docs: clarify documentation for grouped work item counts in register_work_item_tools function

* chore: update plane-sdk dependency to version 0.2.18 and enhance project/workspace member retrieval with pagination and filtering options