feat(uptime): add initial table migration

[JoshFerge]

context: https://github.com/getsentry/team-uptime/issues/23
re-opening from #6690 as the migration needs to come first

[github-actions]

This PR has a migration; here is the generated SQL for ./snuba/migrations/groups.py ()

-- start migrations

-- forward migration events_analytics_platform : 0020_uptime_monitors_init
Local op: CREATE TABLE IF NOT EXISTS uptime_monitor_checks_local (organization_id UInt64, project_id UInt64, environment LowCardinality(Nullable(String)), uptime_subscription_id UUID, uptime_check_id UUID, scheduled_check_time DateTime64(3), timestamp DateTime64(3), duration_ms UInt64, region_slug LowCardinality(String), check_status LowCardinality(String), check_status_reason LowCardinality(String), http_status_code UInt16, trace_id UUID, retention_days UInt16) ENGINE ReplicatedReplacingMergeTree('/clickhouse/tables/events_analytics_platform/{shard}/default/uptime_monitor_checks_local', '{replica}') ORDER BY (organization_id, project_id, toDateTime(timestamp), trace_id, uptime_check_id) PARTITION BY (retention_days, toMonday(timestamp)) TTL toDateTime(timestamp) + toIntervalDay(retention_days) SETTINGS index_granularity=8192;
Distributed op: CREATE TABLE IF NOT EXISTS uptime_monitor_checks_dist (organization_id UInt64, project_id UInt64, environment LowCardinality(Nullable(String)), uptime_subscription_id UUID, uptime_check_id UUID, scheduled_check_time DateTime64(3), timestamp DateTime64(3), duration_ms UInt64, region_slug LowCardinality(String), check_status LowCardinality(String), check_status_reason LowCardinality(String), http_status_code UInt16, trace_id UUID, retention_days UInt16) ENGINE Distributed(`cluster_one_sh`, default, uptime_monitor_checks_local, cityHash64(reinterpretAsUInt128(trace_id)));
-- end forward migration events_analytics_platform : 0020_uptime_monitors_init




-- backward migration events_analytics_platform : 0020_uptime_monitors_init
Distributed op: DROP TABLE IF EXISTS uptime_monitor_checks_dist;
Local op: DROP TABLE IF EXISTS uptime_monitor_checks_local;
-- end backward migration events_analytics_platform : 0020_uptime_monitors_init