More type annotations

[bryevdv]

This PR adds type annotations to the following modules

• launcher
• context
• legate
• operation
• timing.*

and enables strict checking of all modules by default (explicit blocklist for remaining modules)

There are a few awkward types / aliases as well as instances of Any that were left in for now. These will be better to handle separately in later PRs

[bryevdv]

FYI @magnatelee follow-on issues from this PR:

• Bump numpy version #191
• Protocol/ABC for launcher types #192
• Clean up incompat overrides for ManualTask #193

[magnatelee]

@bryevdv looks good to me. feel free to merge this once you confirm that all cuNumeric tests pass with this. (we really should automate that process.)

[bryevdv]

./test.py --use=cuda passes locally fo:

                     GPU: Passed   91 of   91 tests (100.0%)

############################################################
### Exiting Stage: GPU tests
###   * Exception Type: None
###   * Elapsed Time: 0:03:45.003129
############################################################

    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
                   total: Passed   91 of   91 tests (100.0%)