Add CodeStyle option to allow users to customer the 'Invoke Delegate With Conditional Access' analyzer.

Since we only apply the options that finally changed, this behavior
should be redundant, but requires us to categorize options in a not-
obvious way.

This type should have been moved originally.

and plumb them through the UI, persistence, analyzer/fixer and
other parts of the system. update the simplifier to use the new options.
update codegen features as necessary.

for name consistency.

.. is selected, use the first codestyle to show a preview.

.. the new CodeStyle options page.

..  and remove dead code.

and reorder some members.

.. the new CodeStyle options UI page.

Notes:
1. UseVarForDeclarations - the option used by some features isn't
onboard, it is to be replaced by the new use var options.

2. Since the existing options are part of public api, we keep the
options' data structure as such and map the type to a corresponding view
which is used to update the UI. Since they were all underlying boolean
options, we introduce a BooleanCodeStyleOptionViewModel that maps to a
CodeStyleOption type and back.

3. update the StyleViewModel to create options using these new view
models.

This adds the xaml and a view model and plugs everything in
to the current tools->options system.

Most fixes are about code style.

Major changes are in:
1. the algorithm to determine if type is apparent in creation or conversion methods.
2. option serialization/deserialization.

Rename several internal types appropriately. Update file names to match
them. etc.

Adding Enforcement Levels to each `use var` option. Enforcement levels are: None, Info, Warning and Error.

To do:
unit tests need to be unbroken
refactoring to base classes and to be more generic
fix xaml styling and remove any hardcoded values.
fix up todo comments in code

localize all the string resources for use var or use explicit typing
analyzers and fixers.

Changed the UI from combinations of radio buttons and check boxes to use
just checkboxes. Also changed how the partitions of `use var` space was
logically represented. We now present 3 options - use var on intrinsic
types, use var where apparent, use var in rest of the places. If all 3
are checked, we universally use var everywhere. If only one or a
combination less than 3 are selected, we use var only in those places.
An unchecked option means, user prefers explicit typing for that
scenario.

Not yet implemented : enforcement levels of the fix, fancy previews that
show results for a combination of choices, integrating the options into
code generation service.

Remove relay command implementation and usages in checkbox view model.
trying another UI approach to make this simpler.