Addresses Preview and Documentation items from #22719

Ensure complete information is consistently captured in a bound tree for an explicit C# conversion implicitly applied by compiler. (#22703)

Fixes #7299. Fixes #19878

* fixed using block

* updated tests after synching master

* PR feedbacks

1. Rename `ILocalInitializer` to `IVariableInitializer`
2. Refactor OperationFactory methods
3. Change type of `IVariableDeclaration.Initializer` from `IOperation` to `IVariableInitializer`

Fixes #22429

changed GetOperation to always return one from root operation tree and never use recovery mode of semantic model.

1. Flatten the loop statement hierarchy to only derive from ILoopStatement
2. Separate out do loops and while loops
3. Separate out the C# and VB for loops due to different semantics and syntax.

Fixes #21282

1. Remove the redundant `UnaryOpertorKind.BitwiseOrLogicalNot` operator
2. Fix VB unary 'Not' to map to `UnaryOpertorKind.LogicalNot` operator
3. Add doc comments for all the unary and binary operator kinds.

1. Add IsChecked flag for IIncrementExpression and ICompoundAssignmentExpression
2. Add back VB specific binary operator kinds
3. Add more unit tests and fix baselines of existing tests

This implements a bunch of changes to the IOperation representation for binary operator, unary operator and increment expressions.

1. #8834: Simplify `UnaryOperatorKind` to only contain the operator kind values instead of a matrix of operator and operand kinds.
2. #8835: Simplify `BinaryOperatorKind` in similar manner as above.
3. #8825: Add `IUnaryOperatorExpression.IsChecked` flag. Cyrus has already added the `IUnaryOperatorExpression.IsLifted` flag.
4. #8846: Add `IBinaryOperatorExpression.IsChecked` and `IBinaryOperatorExpression.IsCompareText` flags Cyrus has already added the `IBinaryOperatorExpression.IsLifted` flag.
5. #21283: Add `IIncrementExpression.IsDecrement` and `IIncrementExpression.IsPostfix` flags and remove PostFix/Prefix Increment/Decrement from `UnaryOperatorKind` enum.

This change also fixes #8848 and #8843 as the matrix operation kind enums no longer exist.

* Expose if a Binary/Unary operator was 'Lifted' at the IExpression level.

* Update public API.

* Share computed value.

* Remove unnecessary extension.

* Update test code.

* Remove extension method.

* Fixup tests.

* Fixup tests.

* Fixup tests.

* Fix instances of Invalid operations with nullable

* Compound assignments also need to state if they're lifted.

* Move tests.

* Move tests.

* Move tests.

* Simplify comment.

* Case things consistently.

* Use F instead of Foo.  Because Foo is bad.