fix(collaboration): harden the mention notification endpoint

[fschade]

Description

• the requester now has to have access to the file
• recipients are deduped
• a recipient that cannot be resolved no longer drops the notification for everyone else
• errors map to 400/403/404 instead of 500
• remove unused type field is gone from the request body.
• move the mention endpoint to graph

Related Issue

• Fixes collaboration @user mentions review #3128
• Needs feat: add endpoints to mention users in a drive-item libre-graph-api#64
• Dep fix: update the user mention endpoint web#3114
• Update feat: add mention users for TipTap web#3060

How Has This Been Tested?

• unit tests

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Technical debt
• Tests only (no source changes)

Checklist:

• Code changes
• Unit tests added
• Acceptance tests added
• Documentation added

[codacy-production]

Up to standards ✅

🟢 Issues 0 issues

Results:
0 new issues

View in Codacy

🟢 Metrics 43 complexity · -46 duplication

Metric	Results
Complexity	43
Duplication	-46

View in Codacy

🟢 Coverage 73.28% diff coverage · +0.13% coverage variation

Metric	Results
Coverage variation	✅ +0.13% coverage variation (-1.00%)
Diff coverage	✅ 73.28% diff coverage

View coverage diff in Codacy

Coverage variation details

	Coverable lines	Covered lines	Coverage
Common ancestor commit (8504e29)	84010	19259	22.92%
Head commit (ab23c19)	83982 (-28)	19359 (+100)	23.05% (+0.13%)

Coverage variation is the difference between the coverage for the head and common ancestor commits of the pull request branch: <coverage of head commit> - <coverage of common ancestor commit>

Diff coverage details

	Coverable lines	Covered lines	Diff coverage
Pull request (#3297)	116	85	73.28%

Diff coverage is the percentage of lines that are covered by tests out of the coverable lines that the pull request added or modified: <covered lines added or modified>/<coverable lines added or modified> * 100%

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