feat: init kcp core api

[ffforest]

Stuff included in this PR:

• Management Lifecycle (CRUDL) of core models in kcp: org, source, project, stack, workspace, backend
• Execution Lifecycle (build, preview, apply, destroy) on stacks
• Persistence for said core models with SQL DB
• Local (for testing only) and remote source
• Local (for testing only) and remote storage for states and specs

Stuff incoming:

• Lifecycle for workspace config models:, variableSets, matchingRules, etc
• Project and stack initialization via KCP
• Code quality improvement (UT, re-org, database constraints, etc)
• Quality of life improvement (Get by name, remote, etc)

[coveralls]

Pull Request Test Coverage Report for Build 8747462552

Details

• 1731 of 3346 (51.73%) changed or added relevant lines in 78 files are covered.
• 24 unchanged lines in 3 files lost coverage.
• Overall coverage decreased (-1.1%) to 54.465%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
pkg/infra/persistence/backend_model.go	25	27	92.59%
pkg/server/util/ctxutil.go	3	5	60.0%
pkg/server/config.go	0	3	0.0%
pkg/domain/constant/source.go	8	12	66.67%
pkg/domain/constant/stack.go	6	10	60.0%
pkg/domain/entity/backend.go	4	8	50.0%
pkg/domain/request/util.go	44	48	91.67%
pkg/server/handler/types.go	3	7	42.86%
pkg/server/handler/backend/types.go	0	5	0.0%
pkg/server/handler/organization/types.go	0	5	0.0%

Files with Coverage Reduction	New Missed Lines	%
pkg/engine/operation/parser/parser.go	3	79.27%
pkg/engine/operation/parser/spec_parser.go	4	56.1%
pkg/engine/operation/models/change.go	17	51.9%

Totals
Change from base Build 8737887617:	-1.1%
Covered Lines:	8393
Relevant Lines:	15410

---

💛 - Coveralls

[adohe]

/lgtm