Address more feedback from design meeting and expose IOperation.IsExpression and IOperation.IsStatement properties

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

Fixes #22429

* Adding cobyrc file for testing

* Adding isImplicit info to ioperation tests

* Adding Language name to the test dumper

* Formatting change to test dumper

* Removing cobyrc file

* Fixing more tests

* Resolving conflicts

* Moving the language to assert check

* Resolving conflicts

* Reacting to merge conflict

Fixes #22006

Fixes #22008

There might be some more API changes based on the open issues mentioned in #22008

addresses more PR feedbacks

Fixes https://github.com/dotnet/roslyn/issues/21748

1. Fix test issues
2. Remove IHasDynamicArgumentsExpression interface and move the Arguments property from it to individual IDynamicXXXExpression nodes.
3. Adjust the extension methods for GetArgumentName and GetArgumentRefKind accordingly.

In preparation for a merge of features/ioperation to master, we have decided to internalize all the IOperation APIs which are either not tested or not reviewed by the design team.
This includes the following APIs with bugs tracking reviewing/adding tests for them: IArrayElementReferenceExpression(https://github.com/dotnet/roslyn/issues/22006), IAwaitExpression(https://github.com/dotnet/roslyn/issues/22007), ICatchClause(https://github.com/dotnet/roslyn/issues/22008), IEndStatement(https://github.com/dotnet/roslyn/issues/22004), IPlaceholderExpression(https://github.com/dotnet/roslyn/issues/21294), ISizeOfExpression(https://github.com/dotnet/roslyn/issues/21296), IStopStatement(https://github.com/dotnet/roslyn/issues/21297), ITryStatement(https://github.com/dotnet/roslyn/issues/22008), ITypeOfExpression(https://github.com/dotnet/roslyn/issues/22003), IWithStatement(https://github.com/dotnet/roslyn/issues/22005)

This change also includes a simple API rename: IMethodBindingExpression renamed to IMethodReferenceExpression(https://github.com/dotnet/roslyn/issues/21289).

1. Add Locals property to ILoopStatement
2. Remove IterationVariable from foreach loops and VB ForTo loops.
3. Add InvalidCondition to Do loops for VB error cases.
4. Rename property AddLoopBottomExpressionList to NextVariables
5. Add relevant unit tests
6. Remove ISyntheticLocalReferenceExpression and SyntheticLocalKind

Remove IsDeclaration: False from ILocalReferenceExpression and IFieldReferenceExpression. Adding back is tracked by #21798

Fixes #8882

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

Fixes #20114 and #20122

* Tagging VB/C# Ioperation tests

* Fix the Wrong Tagging

* Adding ioperation tests for WhileUntilLoopStatement

* Addressing Feedback

* Removing redundant Nested tests

* Removing the empty lines