#5972 fix npm install and remove checkcesium

[MV88]

Description

This pr fixes the npm script for project that was running the post install script due to the fact that mapstore is considered a library atm for projects

it also fixes a build problem in project with "html-to-draftjs": "1.5.0",

and it removes the check cesium script since is no longer needed

Please check if the PR fulfills these requirements

• The commit message follows our guidelines: https://github.com/geosolutions-it/MapStore2/blob/master/CONTRIBUTING.md
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

What kind of change does this PR introduce? (check one with "x", remove the others)

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• CI related changes
• Other... Please describe:

Issue

What is the current behavior?

#5792

What is the new behavior?

Now mapstore and newly created project have no longer the error

Breaking change

Does this PR introduce a breaking change? (check one with "x", remove the other)

• Yes, and I documented them in migration notes
• No

Other useful information

for a new created project i tested

• npm install from scratch with no error
• the whole process from creation to build the final war with no error
• that cesium is still working by opening a the 3d viewer

for mapstore

• npm install from scratch with no error
• the whole process from creation to build the final war with no error

[coveralls]

Coverage decreased (-0.009%) to 83.533% when pulling 6b502b8 on MV88:5792_npm_install_prj into 5663c6e on geosolutions-it:master.

[tdipisa]

@MV88 can you please backport this to 2020.02.01?