rename "ext" to "instrumentations" and "exporters"

[toumorokoshi]

Now that open-telemetry/opentelemetry-specification#539 has landed, it would be great to adhere to the standard package names. I'm working with other languages as well.

For us, I think we should start by naming everything new as an "exporter" or "Instrumentation". And then a followup PR to rename.

We should do this work before 1.0 / GA, while all packages are in beta.

[lzchen]

Good idea. I'm assuming the current Pypi packages also have to be deprecated for the new ones to replace them?

[lzchen]

Finished package renaming with this release. Old packages on Pypi have been deprecated. As discussed, will monitor traffic of old downloads and delete old packages within the next month.

[kaos]

why delete old packages? that's just causing headaches, no?

[codeboten]

Hi @kaos, we debated this for a long time across multiple SIG meetings and decided to ultimately delete the old packages as we were seeing users coming in with questions after accidentally installing packages named ext.

We were hoping this decision would reduce the confusion and maintenance burden as we were preparing to release the first stable version of OpenTelemetry python.