Removed Component base class and external_samples (wpilibsuite#358)

* Modified uploadProject: removed the saveProjectInfo call so that older projects will get upgraded.

* Changed upgradeProjectIfNecessary to be synchronous by using await on each upgradeFrom_xxx_to_yyy call.
Otherwise the project is upgraded asynchronously and the app fetches the modules before they are upgraded.

* Deleted external_samples files and the corresponding json file.

* Modified python tools to produce information about components, including whether
a class is a component, the component port name (which will show next to the
input socket on the mrc_component block), and the component port type (a single
string consisting of one or more port types separated by two underscores).

Updated generated .json files.

Updated typescript code that uses the .json files.

* Modified pascalCaseToSnakeCase to work better for wpilib class names such as AddressableLED and PWMSparkMax.
Removed snakeCaseToPascalCase, which is not used.

* Updated typescript code related to port, component, and mechanism blocks.
Added PortType enum and functions to convert from a string to a PortType array and back.
Added code to upgrade expansion hub motor and servo components.
Added code to upgrade port type strings.

* Removed methods opmode_start, opmode_periodic, and opmode_end from Mechansim class.
Removed code that generated opmode_start, opmode_periodic, and opmode_end in the Robot.
Removed code that generated calls to robot methods opmode_start, opmode_periodic, and opmode_end in an opmode.
Added upgrade code that changed the opmode_periodic method def in a Mechanism to be editable and deletable.

* Add warnings to mrc_component and mrc_call_python_function blocks if the component class no longer exists.

* Put back opmode_start, opmode_periodic, and opmode_end methods.

* Changed mrc_port extraState to use an array to store the port types.

Author: lizlooney