Logic App trigger extensions should load the extensions based upon workflow definition

#### What problem would the feature you're requesting solve? Please describe.
Logic App extension registers the dynamic function corresponding to each workflow definition, currently all the extensions are getting loading during startup which hampers the cold startup time.

#### Describe the solution you'd like
Currently the extension probing is based upon function.json and Azure function static marker indicates what all the extensions need to be loaded. But the Logic App does not have these function.json as it registers the function for each workflow dynamically which does not having this probing mechanism. For instance , If the extension is not needed by the workflow.json then there is no point to load that extension upfront during start up. This hampers the overall performance during Logic app bootstrap.

#### Describe alternatives you've considered
Currently there is no option other than loading all the trigger extensions (lke Service Bus, Event Hubs, Blob extensions). Going forward we are adding many more connectors may cause huge impact on overall Azure function cold start time.

#### Additional context
Add any other context or screenshots about the feature request here.

Start by tracing Logic App extension registration and workflow definition loading, then compare that path with the current function.json and static-marker probing behavior. Done means only trigger extensions required by a workflow definition are loaded during startup, with cold-start impact evaluated.

Written by the indexing model from the issue text.