V174/22615 fix raw sql member filter repository

[idseefeld]

This closes issue #22615

@AndyButland I know you thought this could be done in 17.5, but I double checked with the protected branch for release-17.4.0 and that already contains the raw sql without using ISqlSyntaxProvider escaping.

[github-actions]

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[Copilot]

Pull request overview

This PR addresses cross-database compatibility issues in MemberFilterRepository by removing provider-specific raw SQL identifier quoting and switching to ISqlSyntaxProvider for quoting/escaping, enabling the combined (content + external) member filter query to work on more database providers.

Changes:

• Updated MemberFilterRepository UNION query SQL to use ISqlSyntaxProvider for quoting table/column/alias identifiers.
• Standardized the UNION DTO column mappings to match new projected column names.
• Exposed a few DTO table/column name constants so the repository can reference them when building quoted SQL.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

File	Description
src/Umbraco.Infrastructure/Persistence/Repositories/Implement/MemberFilterRepository.cs	Reworks raw SQL to quoted identifiers via ISqlSyntaxProvider; updates projection aliases and DTO mappings for the UNION result.
src/Umbraco.Infrastructure/Persistence/Dtos/MemberDto.cs	Makes MemberDto.TableName public so it can be reused when building quoted SQL.
src/Umbraco.Infrastructure/Persistence/Dtos/Member2MemberGroupDto.cs	Makes MemberGroupColumnName public for reuse in repository SQL.
src/Umbraco.Infrastructure/Persistence/Dtos/ExternalMember2MemberGroupDto.cs	Makes MemberGroupColumnName public for reuse in repository SQL.

[Copilot]

MapOrderByColumn() can return a quoted email identifier for ORDER BY, and the UNION column names come from the first SELECT (content members). In BuildContentMemberSql, the email projection is currently m.Email without an alias, so the result column name will be Email (not email) and ORDER BY "email" will fail on case-sensitive/quoted identifier DBs (e.g. PostgreSQL). Alias the email projection to the same name used elsewhere (e.g. email) so the UNION output, DTO mapping, and ordering all align.

Suggested change

	m.{QCol("Email")},
	m.{QCol("Email")} AS {QName("email")},