NIFI-15258 Added API for Connectors (#70)

NIFI-15259: Adding web context interface for custom Connector UIs.
NIFI-15322: Require all property descriptors within a PropertyGroup / ConfigurationStep are unique (#27)
NIFI-15326: Adding support for connector configuration step documentation. (#28)
NIFI-15312: Moved SecretsProvider / SecretsManager to framework instead of api; added description to Secret and updated ParameterProvider to allow more specific fetching of parameters; cleaned up Connector validation logic (#29)
NIFI-15343: Adding providerId to Secret. (#30)
NIFI-15258: Enable Custom UI to retrieve connector with flow contexts (#33)
NIFI-15352: Added getFullyQualifiedName to secret, to encapsulate the combination of group and name (#35)
NIFI-15352: Added getFullyQualifiedName to SecretReference
NIFI-15315 Add support for assets in Connectors (#31)
NIFI-15361: Removing documentation from ConfigurationStep. (#38)
NIFI-15369: Allow ConfigurationStep to depend on another (ConfigurationStep,Property) tuple (#39)
NIFI-15356: Introducing the ConnectorWebMethod. (#37)
NIFI-15353: Adding documentation writers for connectors. (#40)
NIFI-15428: If non-existent property value is set, connector should be invalid. (#43)
NIFI-15427: Added drainFlowFiles(FlowContext) method to Connector (#42)
NIFI-15440: Implementation of ConnectorActions (#47)
NIFI-15446: Updated JavaDocs to clarify how invocations of Connector Methods work (#45)
NIFI-15461: Fixed bug that caused system tests to fail (#48)
NIFI-15451: Provide ability for Connectors to lookup Bundles available for a given component type (#46)
NIFI-15485: Include provider name when providing fqn for secrets (#52)
NIFI-15467: Allow Connectors to specify bundle compatability when upd… (#54)
NIFI-15536: Change Connector API to use DescribedValue vs AllowableValue (#60)
NIFI-15514: Ensure that when AbstractConnector is started, it includes all components, not just processors and controller services; code cleanup (#57)
NIFI-15538: When starting/stopping components allow specifying whether or not the action should be recursive; code cleanup and simplification to use a Virtual Thread to execute code sequentially instead of chaining CompletableFutures. (#61)
NIFI-15480: Added DropFlowFileSummary, ability to drop FlowFiles from a ConnectionFacade / ProcessGroupFacade (#62)
NIFI-15557: Allow Connectors to enable a Controller Service using overridden property values (#63)
NIFI-15565: Code cleanup (#64)
NIFI-15621: Allow Configuration to Validate with ValidationContext (#69)

Co-authored-by: Mark Payne <markap14@hotmail.com>
Co-authored-by: Matt Gilman <matt.c.gilman@gmail.com>
Co-authored-by: Bryan Bende <bbende@apache.org>
Co-authored-by: Bob Paulin <bob@bobpaulin.com>
Signed-off-by: David Handermann <exceptionfactory@apache.org>