Switch to Poetry for dependency management

[brylie]

We currently use pip to manage project dependencies. However, pip has some limitations that may be worth considering:

• doesn't use pyproj.toml
• doesn't automatically add new project dependencies to requirements.txt
• no inbuilt way to upgrade all dependencies to the latest compatible versions
• can't automatically activate environment variables contained in a .env file

The Poetry project resolves most of the above issues and has a plugin to source .env file environment variables automatically when activating the Poetry virtual environment (related to #30).

Further context

We are currently using pip because it is the defacto Python package manager, so it might necessitate fewer steps to get a development environment running. However, it may not be too much of a hurdle for developers to install Poetry instead.

[brylie]

@Upasanadhameliya thoughts? Have you worked with Poetry before?

[Upasanadhameliya]

I haven't worked on it before, yet I like the idea and would be interested in checking it out and would try to implement the same 😃

[Upasanadhameliya]

@brylie I would like to work on this task. Please assign me the same 😸