Rename offline to offchain

[Cmdv]

Description

this fixes #1532

Checklist

• Commit sequence broadly makes sense
• Commits have useful messages
• New tests are added if needed and existing tests are updated
• Any changes are noted in the changelog
• Code is formatted with fourmolu on version 0.10.1.0 (which can be run with scripts/fourmolize.sh)
• Self-reviewed the diff

Migrations

• The pr causes a breaking change of type a,b or c
• If there is a breaking change, the pr includes a database migration and/or a fix process for old values, so that upgrade is possible
• Resyncing and running the migrations provided will result in the same database semantically

If there is a breaking change, especially a big one, please add a justification here. Please elaborate
more what the migration achieves, what it cannot achieve or why a migration is not possible.

[kderme]

A new .sql file is probaby needed since the schema has changed.
Also could you fill the autogenerated check-list of the pr, especially the Migration paragraph which is relevant here?

[sgillespie]

There are some build failures in CI

[sgillespie]

There are still 2 failing tests:

Migration is idempotent:                                 2023-10-17 12:58:24.330 UTC [143] ERROR:  relation "pool_offline_fetch_error" does not exist
2023-10-17 12:58:24.330 UTC [143] STATEMENT:  CREATE INDEX IF NOT EXISTS idx_pool_offline_fetch_error_pmr_id ON pool_offline_fetch_error (pmr_id);
ExitFailure 3

Errors in file: /tmp/migrate-2023-10-17T12:58:24.118194028Z.log

FAIL
      Exception: ExitFailure 1
      Use -p '/Migration is idempotent/' to rerun this test only.

    Insert foreign key missing:                              2023-10-17 12:58:24.350 UTC [147] ERROR:  constraint "unique_off_chain_pool_fetch_error" for table "off_chain_pool_fetch_error" does not exist
2023-10-17 12:58:24.350 UTC [147] STATEMENT:  INSERT INTO off_chain_pool_fetch_error ("pool_id", "fetch_time", "pmr_id", "fetch_error", "retry_count") VALUES (1, '2023-10-17 12:58:24.348073899Z', 1, 'too good', 5) ON CONFLICT ON CONSTRAINT unique_off_chain_pool_fetch_error DO UPDATE SET "pool_id" = EXCLUDED."pool_id" RETURNING id ;
FAIL
      Exception: DbInsertException "OffChainPoolFetchError" (SqlError {sqlState = "42704", sqlExecStatus = FatalError, sqlErrorMsg = "constraint \"unique_off_chain_pool_fetch_error\" for table \"off_chain_pool_fetch_error\" does not exist", sqlErrorDetail = "", sqlErrorHint = ""})
      Use -p '/Insert foreign key missing/' to rerun this test only.

[sgillespie]

LGTM!