enhancement: make sequential blocks trigger configurable

[lostman]

Description

This PR adds an option to relax the requirement that indexed blocks must be consecutive and that there can be no gaps. This is done by specifying --allow-non-sequential-blocks flag when starting the indexer service.

Testing steps

1. Run fuel-indexer with --allow-non-sequential-blocks and confirm with psql that the trigger has been removed:

cargo run -p fuel-indexer -- run --fuel-node-host beta-4.fuel.network --fuel-node-port 80 --replace-indexer --run-migrations --manifest examples/fuel-explorer/fuel-explorer/fuel_explorer.manifest.yaml --allow-non-sequential-blocks

postgres=> \d fuellabs_explorer.indexmetadataentity;
             Table "fuellabs_explorer.indexmetadataentity"
    Column    |         Type          | Collation | Nullable | Default
--------------+-----------------------+-----------+----------+---------
 id           | character varying(64) |           | not null |
 time         | numeric(20,0)         |           | not null |
 block_height | integer               |           | not null |
 block_id     | character varying(64) |           | not null |
 object       | bytea                 |           | not null |
Indexes:
    "indexmetadataentity_pkey" PRIMARY KEY, btree (id)

2. Run fuel-indexer with --allow-non-sequential-blocks and confirm with psql that the trigger has been added:

cargo run -p fuel-indexer -- run --fuel-node-host beta-4.fuel.network --fuel-node-port 80 --replace-indexer --run-migrations --manifest examples/fuel-explorer/fuel-explorer/fuel_explorer.manifest.yaml

postgres=> \d fuellabs_explorer.indexmetadataentity;
             Table "fuellabs_explorer.indexmetadataentity"
    Column    |         Type          | Collation | Nullable | Default
--------------+-----------------------+-----------+----------+---------
 id           | character varying(64) |           | not null |
 time         | numeric(20,0)         |           | not null |
 block_height | integer               |           | not null |
 block_id     | character varying(64) |           | not null |
 object       | bytea                 |           | not null |
Indexes:
    "indexmetadataentity_pkey" PRIMARY KEY, btree (id)
Triggers:
    trigger_ensure_block_height_consecutive BEFORE INSERT OR UPDATE ON fuellabs_explorer.indexmetadataentity FOR EACH ROW EXECUTE FUNCTION ensure_block_height_consecutive()

Changelog

• add remove_ensure_block_height_consecutive_trigger query
• change where create_ensure_block_height_consecutive_trigger is called: previously when the table was created; currently: when the indexer executor starts

[ra0x3]

• Looks good thanks @lostman
• All that's missing is just adding the new arg to the QA script

.arg("--allow-non-sequential-blocks")

[ra0x3]

Thanks, will defer to @deekerno