[Extra/rest 2.5] add relayer stat

[satawatnack]

Implementation details

ADD IBC relayer stat to support this implementation

Table relayer_tx_stat_days

Column 1	Type
date	CustomDate	PK
port	String	PK, FK
channel	String	PK, FK
address	String	PK
ibc_received_txs	Integer
last_update_at	CustomDateTime

Note:

CREATE TABLE RELAYER_TX_STAT_DAYS(
  DATE DATE NOT NULL,
  PORT VARCHAR (20) NOT NULL,
  CHANNEL VARCHAR (20) NOT NULL,
  ADDRESS  VARCHAR (255) NOT NULL,
  IBC_RECEIVED_TXS INT,
  LAST_UPDATE_AT TIMESTAMP,
  CONSTRAINT PK_RELAYER_STATS PRIMARY KEY (DATE,PORT,CHANNEL,ADDRESS),
  FOREIGN KEY (PORT,CHANNEL) REFERENCES CHANNELS(PORT,CHANNEL)
);

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[RogerKSI]

Note: merge after chain upgrade v2.5.

[RogerKSI]

LGTM. let me test on testnet.