This changes Turborepo config in the workspace root to be explicit.
Explicity in this case means that all tasks are defined manually and all
inputs are also specified manually.

While that might seem redundant, this allows to orchestrate and adjust
tasks more carefully - ignoring some files while taking other files into
account, only hashing and providing project-specific variables,
explicitly reviewing and specifying dependencies. That might come in
handy in the future.

There's an alternative way to approach this, which is to have every
package contain "turbo.json" file, however, for now the flat approach
has been chosen as it seems to be the most cleanest and easiest to
review.

@modrinth/i18n will be a package that contains the common messages that
are used by two or more packages, as well as utilities for working with
localisation, such as `defineMessage` macro and locale files resolver
abstraction.

It is pre-built in a manner that allows for harsh tree-shaking, meaning
the messages that will not be used, should not be included by the
bundlers.

All messages are also defined using the `defineMessage` macro that
cleans the descriptors and pre-parses `defaultMessage` to AST, which
serves both as validation, as well as allows its use as fallback even in
environments devoid of bundled-in compiler. When all other code parts
are switched to use this macro, this might allow to exclude messages
files for English language, potentially saving on removed duplication.

Please note that currently `defineMessages` does not include
`defaultMessage` because it is expected that consumers of
`@modrinth/i18n` will include and pre-compile extracted messages file.
This can be overriden by setting `MODRINTH_I18N_DEFAULT_MESSAGE`
environment variable to `1`.