initial changes for KPI value writer and api

proto/kpi_value.proto

scripts/run_tests_locally-kpi-value-API.sh

scripts/run_tests_locally-kpi-value-writer.sh

src/kpi_management/kpi_value_writer/service/__init__.py

src/kpi_management/requirements.in

src/kpi_management/service/__init__.py

src/kpi_management/service/database/__main__.py

src/kpi_management/tests/KPI_configs.json

src/kpi_management/tests/__init__.py

src/kpi_manager/tests/test_kpi_manager.py

src/kpi_manager/tests/test_messages.py

src/kpi_value_api/__init__.py

src/kpi_value_api/client/__init__.py

src/kpi_value_api/service/__init__.py

src/kpi_value_writer/.gitlab-ci.yml

src/kpi_value_writer/Dockerfile

src/kpi_value_writer/README.md

src/kpi_value_writer/__init__.py

src/kpi_value_writer/service/KpiValueComposer.py

src/kpi_value_writer/service/KpiValueWriter.py