fix: key proposalPKey added to the event handler to eliminate error

[yoganandaness]

Description

key proposalPKey added to the event handler to eliminate error and facilitate saving of data in event logs

Motivation and Context

The required key proposalPKey was not passed to the logging for the event PROPOSAL_CO_PROPOSER_INVITE_EMAIL_SENT thereby resulting in following error

`Error was detected!

Context: {"exception":{"name":"TypeError","message":"Cannot read properties of undefined (reading 'toString')","stack":"TypeError: Cannot read properties of undefined (reading 'toString')\n at /home/node/app/build/src/eventHandlers/logging.js:188:111\n at Generator.next ()\n at /home/node/app/build/src/eventHandlers/logging.js:8:71\n at new Promise ()\n at __awaiter (/home/node/app/build/src/eventHandlers/logging.js:4:12)\n at loggingHandler (/home/node/app/build/src/eventHandlers/logging.js:27:16)\n at EventBus. (/home/node/app/build/src/events/eventBus.js:23:27)\n at Generator.next ()\n at fulfilled (/home/node/app/build/src/events/eventBus.js:5:58)\n at process.processTicksAndRejections (node:internal/process/task_queues:105:5)"}}
Platform: duo-backend
Environment: staging
Title: Error handling logs for event PROPOSAL_CO_PROPOSER_INVITES_UPDATED
Source: duo-backend-staging-6b99d9c66c-rmgff

Timestamp: 2025-10-14T14:05:33.508Z

Visit graylog for more information: https://it-graylog.esss.lu.se/`

How Has This Been Tested

Tested locally

Fixes

Changes

Added proposalPKey as parameter when sending out the event for PROPOSAL_CO_PROPOSER_INVITE_EMAIL_SENT

Depends on

Tests included/Docs Updated?

• I have added tests to cover my changes.
• All relevant doc has been updated