Add feature flag to avoid waiting for AI activation in tests

Context

This MR adds two feature flags to help test Adaptive Issuance. adaptive_issuance.force_activation that is used to speed up activation by bypassing the wait for the vote to pass. adaptive_issuance.as_enable that is planned to be used to test future improvements/features.

These flags will be used in future MRs introducing new tests.

A follow-up action could be to improve this feature flag by adding a parameterizable delay before activation (tell me what you'd like in the comments).

Manually testing the MR

dune exec src/proto_alpha/lib_protocol/test/integration/main.exe \ -- --file test_adaptive_issuance_launch.ml to test all the ai launch related tests

dune exec src/proto_alpha/lib_protocol/test/integration/main.exe \ -- --file test_adaptive_issuance_launch.ml -m force_activation

to test only the newly introduced test that uses the force_activation feature flag.