[PORT] Revert the reusing of json converters

[tomlm]

Port this change from botbuilder-dotnet/master branch:
microsoft/botbuilder-dotnet#3783

Description

Fixes microsoft/botbuilder-dotnet#3769 TestBot.Json broken in master

Context

microsoft/botbuilder-dotnet#3711 introduced a cache for json converters, in which json converters are created once when converting first json, and reused in later json conversion.

The issue is, those json converters are stateful, in which SourceContext captured the state (the call stack). In order to make it work as expected, the call stacked must be initialized with a SourceRange pushed to bottom of the stack, and this initialization only happens when creating those converters.

So reusing the converters will not re-initializing the state, in this specific case, will not push a SourceRange into stack. Then all the following source range registering will not get a path value, and fail to load.

Fix

The fix in this PR is simply reverting the cache and reusing behavior of converters.

If for performance reason or any other reasons we want to reuse the converters, we need an approach to reset the converters with state. Could simplify be making a sub-class of JsonConverter and add a reset method, or other approach.

Anyhow, leave the systematic to @tomlm or @willportnoy.

Changed projects

• Microsoft.Bot.Builder.Dialogs.Declarative
• Microsoft.Bot.Builder.TestBot.Json

[gabog]

@boydc2014, does this apply to JS? Can you close it if it doesn't.

[chon219]

We don't have this in JS, closing this issue.