V2 build scripts for ci

[NorseGaud]

Updates since review:

1. build/install/uninstall scripts moved into scripts directory (out of root) + paths in scripts changed to accommodate dependency installation scripts for each distro
2. Symlinking in install script has been removed. Output after install has been modified

Build Script changes:

1. Variables used throughout are now located in eosio_build.sh (D.R.Y)
2. BOOST, Mongo+mongolibs, CMAKE, and others are now installed into and using ~/lib,bin,etc,data (Eliminates need for root as much as possible)
3. MongoDB launch command uses ~/ paths for configs, logs, etc (CI/CD pipeline as well)
4. Installation from source is closer to what the developer portal suggests
5. Ubuntu build script MongoDB installation accounts for 16.04 or 18.04 versions (18 gets v4, vs v3; v3 doesn't exist for 18)
6. Wrapped apt/yum/brew update with warning
7. Better cleanup script to handle old installs or new
8. Fix for gettext being keg-only

CMakeModules changes:

1. LLVM/WASM path is now ~/opt/llvm + FindWasm using ~/opt/llvm for both darwin and linux

Test changes

1. tests/nodeos_run_test.py -> Setting currentBlockNum later in code so that a slow machine that generates too many blocks won't fail the tests

Notes:

• We can now copy and paste almost everything between OS build scripts. (Time savings for maintenance)
• We have consistency between Linux and Mac paths.
• Build script are used to create images, "shifting left" the responsibility of maintaining them to DevOps, instead of both Dockerfiles AND build scripts.
• Output of build scripts are much cleaner and easier to follow.

VM Image Speed Improvements:

• mojave build from 8m to 5m
• centos build from 15m to 8m