NVDA source: remove Windows 7 constant mentions (#15665)
Closes #15651
Summary of the issue:
Remove Windows 7 (winVersion.WIN7_SP1) constant mentions from NVDA source code.
Description of user facing changes
None
Description of development approach
Mostly edited File Explorer app module and UIA objects code:
Remove bulk of WorkerW, MetadataEditField, status bar fetcher, and Start menu/search suggestions handling on Windows 7
Removed text range exception check from UIA objects
