Updated top level dependencies and fixed the build.

[kadishmal]

• Updated Lerna to the latest version.
• Updated Webpack dependency in cdkdx which has an SSL security issue https://github.com/hupe1980/cdkdx/issues/22.
• Updated ClamAV version for Ubuntu run in Docker. Version 0.103.11-1.el7 is no longer available.
• Added build instructions to README.

Build results:

 Lerna (powered by Nx)   Successfully ran target build for 45 projects (2m)

✨  Done in 113.17s.

Test results:

Test Suites: 42 passed, 42 total
Tests:       106 passed, 106 total
Snapshots:   64 passed, 64 total
Time:        7.664 s
Ran all test suites in 27 projects.
✨  Done in 10.13s.