ci: add actions with installing build/test deps

This patch adds actions with installing deps for Debian, FreeBSD, and
OSX operation systems. Also, it adds an action with installing deps for
Jepsen testing. Debian, FreeBSD, and OSX actions should be used before
running tests on the corresponding operation systems. Jepsen action
should be used before running Jepsen tests.

Reasoning:

1. The makefile w/o targets with deps installation is OS-independent.
   It should work on all systems.

2. Deps installation is more about env preparation rather than building
   and testing. Moreover, it is OS-dependent. So it's logical to take it
   outside the makefile into a GitHub action.

3. If we need testing on other operation systems, for example, CentOS,
   we will just create a special action with deps installation for that.
   No changes for the makefile will be needed. All should work out of
   the box.

NO_DOC=ci
NO_TEST=ci
NO_CHANGELOG=ci

.github/actions/install-deps-debian/action.yml

+name: Install Deps Debian
+
+description: Install build and test dependencies on Debian-based systems
+
+runs:
+  using: composite
+  steps:
+    - run: |
+        apt-get --allow-releaseinfo-change update
+        apt-get -y -f install \
+          build-essential \
+          ninja-build \
+          cmake \
+          lua5.1 \
+          luarocks \
+          lcov \
+          ruby-dev \
+          liblz4-dev \
+          autoconf \
+          automake \
+          libtool
+
+        luarocks install luacheck 0.26.1
+        gem install coveralls-lcov
+      shell: bash

.github/actions/install-deps-freebsd/action.yml

+name: Install Deps FreeBSD
+
+description: Install build and test dependencies on FreeBSD systems
+
+runs:
+  using: composite
+  steps:
+    - env:
+        PIP_URL: https://bootstrap.pypa.io/get-pip.py
+      run: |
+        pkg install -y \
+          cmake \
+          gmake \
+          icu \
+          libiconv \
+          python38 \
+          autoconf \
+          automake \
+          libtool
+
+        which python3 || ln -s /usr/local/bin/python3.8 /usr/local/bin/python3
+        python3 -m pip -V || curl -fsSL ${PIP_URL} | python3
+      shell: bash

.github/actions/install-deps-jepsen/action.yml

+name: Install Deps Jepsen
+
+description: Install dependencies for Jepsen testing
+
+runs:
+  using: composite
+  steps:
+    - env:
+        CLOJURE_URL: https://download.clojure.org/install/linux-install-1.10.1.561.sh
+        LEIN_URL: https://raw.githubusercontent.com/technomancy/leiningen/stable/bin/lein
+        TERRAFORM_URL: https://releases.hashicorp.com/terraform/0.13.1/terraform_0.13.1_linux_amd64.zip
+        BIN_DIR: /usr/local/bin
+      run: |
+        apt-get --allow-releaseinfo-change update
+        apt-get -y -f install \
+          openjdk-8-jre \
+          openjdk-8-jre-headless \
+          libjna-java \
+          gnuplot \
+          graphviz \
+          zip \
+          unzip \
+          openssh-client \
+          jq
+
+        curl ${CLOJURE_URL} | bash
+        curl ${LEIN_URL} > ${BIN_DIR}/lein
+        chmod a+x ${BIN_DIR}/lein
+        curl -O ${TERRAFORM_URL}
+        unzip -o $(basename ${TERRAFORM_URL}) terraform -d ${BIN_DIR}
+      shell: bash

.github/actions/install-deps-osx/action.yml

+name: Install Deps OSX
+
+description: Install build and test dependencies on OSX systems
+
+runs:
+  using: composite
+  steps:
+    - run: |
+        # FIXME: Temporary pinned python3 to specific version (python@3.8)
+        # to avoid 'gevent' package installation failure described in
+        # gevent/gevent#1721. Change to python3 when the issue is resolved.
+        PKGS='openssl
+              readline
+              curl
+              icu4c
+              libiconv
+              zlib
+              cmake
+              python@3.8
+              autoconf
+              automake
+              libtool'
+
+        # Try to install the packages or upgrade them if the packages are
+        # already installed.
+        brew install --force ${PKGS} || brew upgrade ${PKGS}
+      shell: bash