[10.0] Query pipeline architecture improvements

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This issue tracks longer-term, architectural changes to the query pipeline.

Issues completed in 9.0 are visible in #31327.

• Represent query parameters with a dedicated type instead of ParameterExpression #35089
• Consider simplifying SQL parameter names (@__city_0 -> @city) #35113
• Introduce a safer mechanism for accessing parameters and disabling SQL caching #36266
• Reference IColumnBase (relational model) from ColumnExpression #36231
• Make SqlNullabilityProcessor into a real ExpressionVisitor #34696
• Rewrite SearchConditionConverter #34905
• Simplify away NonQueryExpression #34768