Use configuration variable to define the dappnodesdk version in the gha workflows

[pablomendezroyo]

Context
The current way of the gha workflows in the DAppNodePackages use by default the latest dappnodesdk version via the command npx @dappnode/dappnodesdk. This approach entails issues whenever a certain version is not stable and it may break the CI/CD in those packages using this tool.

Approach

1. Create an organization configurable variable and use it in the workflows as an env, i.e:

    run: npx @dappnode/dappnodesdk@$DAPPNODE_SDK_VERSION
    env:
        ORGANIZATION_VAR: ${{ vars.ORGANIZATION_VAR }}

2. Modify all the gha workflows to use this env in the dappnodesdk commands. Consider using a script for that