Add 'taplo' to the CI workflow to check the formatting of Cargo.toml files

[ebma]

Context

There is a tool called taplo that can check and format TOML files. Since different IDEs by default have different rules for formatting TOML files, we want to streamline the formatting by using this tool.

TODO

This would ideally be done only after #525 to make sure that the precommit hook is fixed.

• Add taplo to the automated build checks in the Github CI workflow. Only check for wrong formatting with taplo fmt --check but don't correct the formatting in the CI
• Add a configuration file. We can put it into .config/taplo.toml and draw inspiration from the one used for the polkadot-sdk here
• Add instructions to install and use taplo to the README.
• Add taplo fmt to the precommit hook and make it format all the committed files automatically

[ebma]

@pendulum-chain/product a nice-to-have feature for developer experience. Kind of blocked by #525.

[prayagd]

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