Update to JSON.Net 6.0.6

Fixes #1473
Merge branch 'release' into dev
Added description in project.json for all projects
Merge branch 'release' into dev
Fix for #1052 - ViewComponents should support fully qualified names

This change adds the concept of a full-name to viewcomponents. View
components can be invoked using either the short name or long name. If the
provided string contains a '.' character, then it will be compared against
full names, otherwise it will be matched against short names only.

The short name is used for view lookups.

If the name is explicitly set via ViewComponent attribute, then the full
name is the name provided. The short name is the portion of the name after
the last '.'. If there are no dots, then the short name and full name are
the same.

If the name is not set explicitly, then it is inferred from the Type and
namespace name. The short name is the Type name, minus the 'ViewComponent'
suffix (if present). The full name is the namespace of the defining class,
plus the short name.
Rework `ViewDataDictionary` constructors to ensure `ModelMetadata` is never `null`
- `ViewDataDictionary<TModel>` constructors now pass `typeof(TModel)` to base
  `protected` constructors
 - move type compatibility checks into base `ViewDataDictionary`
 - remove `ViewDataDictionary<TModel>.ModelMetadata` override
- don't retrieve `ModelMetadata` twice in a single constructor invocation
- remove newly-unused `protected` properties and use `private` fields in copy
  constructors

Address longstanding problems found (see #1466)
- avoid reusing `ModelMetadata` after `Model` value changes
 - reset `ModelMetadata` backing field in `Model` setter
 - `Model` and `ModelMetadata.Model` could previously get out of sync
- carry `ModelMetadata` forward from an outer scope only if `Model` matches
 - previously two scopes could have different `Model` values but share their
   `ModelMetadata` (and `ModelMetadata.Model`)
 - related to previous item but didn't require `Model` setting; switching
   to a property of the same type as containing `Model` was enough
- avoid NRE if `ViewDataDictionary<int>.Model` is read before it's written
 - problem affected all non-`Nullable` value types
- `ViewDataDictionary.ModelMetadata` setter should throw if value is `null`

nits:
- add and reword doc and code comments
 - `ViewDataDictionary<TModel>` constructors should only inherit base's
   parameter descriptions; have more information in the derived class
- make a few `ViewDataDictionary` properties get-only
- clean up `using` statements in `ViewDataDictionary<TModel>`
- make two constructors `internal`
Correct some `ViewDataDictionary` constructor calls
- ensure correct `ViewData.ModelState` value in a `RazorPage` instance
- let view components inherit `ViewData.Model` from surrounding context
- do not create an isolated `ViewDataDictionary<TModel>` in one HTML helper
 - allows previous `ViewDataDictionary<TModel>` constructor to be `internal`
  - also add comments for that constructor
- change two `ViewDataDictionary` copy constructor calls to avoid uselessly
  copying `Model` and related information from source
Correct code checking for `ViewDataDictionary.ModelMetadata==null`
- `null` checks can generally be removed but in one case needed to
  special-case metadata for `object`

nit: remove duplicate empty `string` check in
`ExpressionMetadataProvider.FromStringExpression()`
Adjust tests to handle new `ViewDataDictionary` invariants
- ensure `ViewDataDictionary` constructors are not passed a `null` or
  `Mock.Of<IModelMetadataProvider>()` instance
 - `ViewDataDictionary` constructors always use the `IModelMetadataProvider`
- `viewData.ModelMetadata` now never `null`
- `ViewDataDictionary<int>.Model` no longer throws if read before it's written
- `ViewDataDictionary.ModelMetadata` now copied to new instances in fewer cases
 - e.g. don't use unusual `object` datatype with customized `ModelMetadata`
More `ViewDataDictionary` tests
- separate and extend `ViewDataDictionary<TModel>` tests
Revert "Revert "Added a functional test for view precompilation""

This reverts commit 6b2ab32885a526bbfacbd7ff2aa7cdcc8e4cde5f.
Adding functional tests for Filters.
Adding the following:
1. ShortCircuiting of Filters.
2. Throwing Exception from different filters.
3. Changing the Order of Controller class.
Updated the ProductsController test to reflect all the filters in one test.