DLT component (and related) improvements

See merge request !16

- deactivated CI/CD pipeline for DLT. It was activated by mistake

- implemented preliminary version of CI/CD pipeline definition for DLT (still not integrated in pipeline)

- removed unneeded genproto.sh script

Merge branch 'feat/dlt-component-connector' of https://labs.etsi.org/rep/tfs/controller into feat/dlt-component

Merge branch 'develop' of https://labs.etsi.org/rep/tfs/controller into feat/dlt-component-connector

- Corrected URLs for multi-container pods
- Added support for DLT component
- Corrected minor errors with service/deployment naming

MockBlockchain:
- Implemented mock-blockchain module to facilitate testing and debugging of DLT connector & workflows
- Added manifests, Dockerfile, etc.

DLT Connector:
- corrected requirements.in
- updated Dockerfile
- WIP: implementation of test_unitary.py

DLT Gateway:
- Improved/extended Dockerfile
- Moved Dockerfile to correct folder
- Corrected import path for proto files

Including the validation of creation of KPIs and their values to the OFC'22

See merge request !15

Consolidating commong fixtures in a single file at the root of the tests folder. Updating ECOC'22 and OFC'22 tests to use it.

Fixing some imports and branching a fixture file for each test case so that they can have particularities.

Including the validation of creation of KPIs and their values to the OFC'22 test set. Also consolidating the fixtures into a single file in the root of the 'src/tests' folder so that all tests can import from it.

Feat/monitoring major functional updates

See merge request !14

Minor code polishing after ECOC'22 demo

See merge request !13

- improved HTTP status code checks

- minor styling improvements in Slice pages

Merge Hackfest material into Develop

See merge request !11

Tutorials cleanup

See merge request !10

Pass on the tutorials to (i) verify that all parts are complete (did not run the installation procedures); (ii) updated instructions on how to select the Python version; (iii) general aestetic changes.

doc/fix: add instructions for ngsdn-tutorial mininet

See merge request !9