Refactor terraform pieces for deploying osm-stats components to Azure

[eternaltyro]

• Refactor terraform code to be compliant with v1.0.11
• Bump AzureRM and random provider versions
• Add lock files to gitignore
• Split the main terraform file into variable, provider and output files
• Fix database resource blocks to update deprecated code
• Use jsonencode for JSON components for better control and readability
• Use hotosm images instead of ARC images
• Use custom OVERPASS_URL value for envvars
• Update formatting and syntax throughout

[eternaltyro]

@dakotabenjamin please review.