Generate seed connector specs on build (airbytehq#7501)

* add specs module with logic to fetch specs on build

* format + build and add gradle dependency for new script

* check seed file for existing specs + refactor

* add tests + a bit more refactoring

* run gw format

* update yaml config persistence to merge specs into definitions

* add comment

* delete secrets migration to be consistent with master

* add dep

* add tests for GcsBucketSpecFetcher

* get rid of static block + format

* DRY up parse call

* add GCS details to comment

* formatting + fix test

* update comment

* do not format seed specs files

* change signature of run to allow cloud to reuse this script

* run gw format

* revert commits that change signature of run

* fix comment typo

Co-authored-by: Davin Chia <davinchia@gmail.com>

* rename enum to be distinct from the enum in cloud

* add missing dependencies between modules

* add readme for seed connector spec generator

* reword

* reference readme in comment

* ignore 'spec' field in newFields logic

Co-authored-by: Davin Chia <davinchia@gmail.com>

airbyte-config/init/src/main/java/io/airbyte/config/init/SeedType.java

@@ -7,7 +7,9 @@
 public enum SeedType {
 
   STANDARD_SOURCE_DEFINITION("/seed/source_definitions.yaml", "sourceDefinitionId"),
-  STANDARD_DESTINATION_DEFINITION("/seed/destination_definitions.yaml", "destinationDefinitionId");
+  STANDARD_DESTINATION_DEFINITION("/seed/destination_definitions.yaml", "destinationDefinitionId"),
+  SOURCE_SPEC("/seed/source_specs.yaml", "dockerImage"),
+  DESTINATION_SPEC("/seed/destination_specs.yaml", "dockerImage");
 
   final String resourcePath;
   // ID field name