Supports of BOOLEAN type, bug fix, and intellisense experience improvement.

[pomgui]

This PR contains:

• Support for BOOLEAN type in escape functions.
• Fix a potential bug
• GDSCode refactoring to improve intellisense experience.

Details

BOOLEAN type

In Firebird3 a true BOOLEAN type has been added, however the escape functions of this driver didn't support it, causing an error GDSCode.CONVERT_ERROR with a message like conversion error from string "1".

Reproduzing the error

Given a table in a Firebird 3 database:

CREATE TABLE test01(b BOOLEAN);

Execute the code:

FB.attach(options, (err, db) => {
    if (err) return closeDB(db, null, err);
    // Get a new transaction
    db.transaction((err, transaction) => {
        if (err) return closeDB(db, transaction, err);
        // insert a record
        transaction.query(`INSERT INTO test01 VALUES ( ${db.escape(true)} )`, [], 
          (err, _) => closeDB(db, transaction, err)
        );
    });
});
/** Helper function */
function closeDB(db, transac, error) {
    if (error) console.error(error.message, 'GDSCode: ', error.gdscode);
    if (transac) {
        if (!error) {
            console.log('commit()');
            return transac.commit(err => closeDB(db, null, err));
        } else {
            console.log('rollback()');
            return transac.rollback(err => closeDB(db, null, err));
        }
    }
    if (db) {
        console.log('detach()');
        db.detach(err => console.error(err));
    }
}

Output:

conversion error from string "1" GDSCode:  335544334
rollback()
detach()

Fix Potential bug

In messages.js, the getClass function was returning a wrong value, because it was right-shifting 30 bits instead of 28.

Consider the following expressions:

CLASS_MASK == 0xF0000000; 
getCode(0x456789234) == 0x1 // it should return 0x5:
(0x456789234 & CLASS_MASK) == 0x050000000
(0x050000000 >> 28) == 0x5
(0x050000000 >> 30) == 0x1

Despite this function is not being used by the driver itself, it is exported, therefore it should return the correct value.

Intellisense experience

The GDSCode has been refactored changing the line comments (// xpto) with documentation comments (/** xpto */). This allows intellisense capable software (like vscode) show this comments to developer.
Also, the definition file now contains the whole list of codes, in order that typescript users has the intellisense benefit as well, and as now it's an enum, the developer can see the list of codes (normally with a Ctrl+space).