Replace 'VSCODE' with a more general 'DEV'

To create the image defined in this dockerfile, we've merged three differend images:
 * storm2/build/base
 * storm2/build/ngx-voms-build [issue-17]
 * storm2/ngx_http_voms_module/.devcontainer
Each image has this own 'yum install' command with the packages needed for that layer.

With this commit, all the packages are installed in a single layer to reduce the image dimension.
All the 'yum install' commands are grouped in the setup.sh script.

* To reduce the image dimension, two RUN commands are merged in one single layer.
* All packages are installed with a single command.
* remove cern and garr mirrors
* the clean commands are the last instructions in the layer
* sudo is installed only in the dockerfile

As written in the best practise: https://docs.docker.com/develop/develop-images/dockerfile_best-practices/#add-or-copy

To create the vscode user, the provide_user.sh script is used. With this script the comand line appearance is improved with colors and branch informations

Update the license format in Dockerfile as an example. These two lines need to be inserted in all the file in the project repo

Only one user is useful: test user and storm user have been removed. The default user has changed name in vscode because is the not-root user commonly used in devcontainer

The patch file needs to be in the project root directory in order to be loaded for the rpm generation.
The patch file needs also to be into the devontainer build directory; this means that, at this moment, we use a copy of the patch file but an alternative solution can be find.

Rebase to openresty 1.19.9.1

See merge request storm2/ngx_http_voms_module!18

* Explicitly install build-time deps needed for this package
* Take the httpg patch from this repo

The script can be used both for the devcontainer and for the continuous
integration.

The debug spec file is not used, but let's keep it aligned with
the other one.

* Start from the upstream SPEC file.
* Use the %{name} macro instead of explicitly repeating openresty-voms
* Use system zlib, openssl and pcre dependencies and do not specify minimum
  versions
* Remove unused macros oroprefix, {zlib,pcre,openssl}_prefix
* The voms_module_prefix macro is assumed
* Mv-ing openresty binary in openresty-voms seems irrelevant
* Don't consider "tapset" files, they don't exist (any more)
* For debug builds use -Og
* Review the packaging script
  - Minimize the list of build-time packages to install
  - Set the voms_module_prefix macro in the .rpmmacros file. The prefix is
    on the command line, with a default
  - Build only the optimized RPM
* Start docker:dind with --tls=false to avoid timeouts during CI

Issue #17

CentOS provides gcc 4.8.5, which has a decent support for C++14
features, enabled with -std=c++1y.

In this way we don't need to bring in the devtoolset software
collection.

Conflict is set against any version of openresty.

In particulare the one in certs shows concrete examples on how to
generate VOMS proxies

The proxies had a wrong VO in the FQANs and couldn't be validated any
more by the VOMS lib. See commit
https://github.com/italiangrid/voms/commit/feeaed

encoding.t was also affected, but didn't require any change, just a
correctly generated proxy.

Apparently the bug mentioned in the (removed) comment has been fixed.
But this showed a bug in our test: http vs HTTP in the pattern to match
in the log.

Issue #17

Refactored openresty-voms docker image

See merge request storm2/ngx_http_voms_module!17

Issue 22

See merge request storm2/ngx_http_voms_module!16

Check it's an SSL request before dereferencing the ssl field of a connection

Closes #26

See merge request storm2/ngx_http_voms_module!15

fix issue #26