Fix TeamsMeetingPolicy docs: remove non-existent params, fix defaults, sync New-/Set-

Changes to New-CsTeamsMeetingPolicy.md and Set-CsTeamsMeetingPolicy.md:

Removed (not exposed as cmdlet parameters):
- AllowedUsersForMeetingContext: in XSD/model but not in cmdlet code
- AllowUserToJoinExternalMeeting: in XSD/model but not in cmdlet code

Fixed duplicates in Set-CsTeamsMeetingPolicy.md:
- AllowedUsersForMeetingContext: appeared twice (now removed entirely)
- AllowExternalNonTrustedMeetingChat: appeared twice, kept the correct version

Fixed incorrect default values (both cmdlets):
- ParticipantSlideControl: was 'Enabled', correct default is 'EveryoneInOrganization'
- VoiceSimulationInInterpreter: was 'Disabled', correct default is 'Enabled'

Added to New-CsTeamsMeetingPolicy.md (were in Set- but missing from New-):
- AutoRecording
- SetRecordingAndTranscriptOwnership

Added to Set-CsTeamsMeetingPolicy.md (were in New- but missing from Set-):
- AllowWatermarkCustomizationForCameraVideo
- AllowWatermarkCustomizationForScreenSharing

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: djyuran0