[DEVOPS-1651] Update the QA deployment alert at the start

[michalchecinski]

🎟️ Tracking

https://bitwarden.atlassian.net/browse/DEVOPS-1651

🚧 Type of change

• 🚀 New feature development
• 🤖 Build/deploy pipeline (DevOps)

📔 Objective

📋 Code changes

• report-deployment-status-to-slack/action.yml: Change failure (true/false) input to event (string: start, failure, success). Add URL parameter. Add step with start event message.
• .github/actions/test-report-deployment-status-to-slack.yml: Change inputs to match new ones. Add start message test.

📸 Screenshots

New starting deployment message. I've tried to format it with a link under string, but it didn't work, and I don't want to spend hours to getting this to work.

⏰ Reminders before review

• Contributor guidelines followed
• All formatters and local linters executed and passed
• Written new unit and / or integration tests where applicable
• Used internationalization (i18n) for all UI strings
• CI builds passed
• Communicated to DevOps any deployment requirements
• Updated any necessary documentation or informed the documentation team

🦮 Reviewer guidelines

• 👍 (:+1:) or similar for great changes
• 📝 (:memo:) or ℹ️ (:information_source:) for notes or general info
• ❓ (:question:) for questions
• 🤔 (:thinking:) or 💭 (:thought_balloon:) for more open inquiry that's not quite a confirmed issue and could potentially benefit from discussion
• 🎨 (:art:) for suggestions / improvements
• ❌ (:x:) or ⚠️ (:warning:) for more significant problems or concerns needing attention
• 🌱 (:seedling:) or ♻️ (:recycle:) for future improvements or indications of technical debt
• ⛏ (:pick:) for minor or nitpick changes