fix(NODE-4186): accept ReadPreferenceLike in TransactionOptions type

[noahsilas]

Description

This commit expands the TransactionOptions type definition to allow values like 'primary'.

What is changing?

Before, the type definition only allowed passing an instance of the ReadPreference class. This differs from documented and common usage. We expand the type definition from ReadPreference to ReadPreferenceLike.

Updating this type annotation will reduce confusion for Typescipt users of the library.

Is there new documentation needed for these changes?

No, this makes the types match the existing documentation more closely. For instance, in https://www.mongodb.com/docs/drivers/node/current/fundamentals/transactions/#transaction-settings, this API is documented as accepting a string:

const transactionOptions = {
readPreference: 'primary',
readConcern: { level: 'local' },
writeConcern: { w: 'majority' },
maxCommitTimeMS: 1000
};
session.startTransaction(transactionOptions);

What is the motivation for this change?

The documented code snippet above should not cause a Typescript error.

We can also see in https://github.com/mongodb/node-mongodb-native/blob/48fa588362/src/transactions.ts#L108 that the transaction constructor will pass its options through to ReadPreference.fromOptions, which will handle coercing a string into a ReadPreference instance, so the documentation appears to be correct while the type definition is lacking.

Double check the following

• Ran npm run check:lint script
• Self-review completed using the steps outlined here
• PR title follows the correct format: <type>(NODE-xxxx)<!>: <description>
• Changes are covered by tests
• New TODOs have a related JIRA ticket

[nbbeeken]

@noahsilas Thanks for the help here! I've added a test to just double check that this keeps working at runtime (as it already has been)

[noahsilas]

Thanks for the support on the testing @nbbeeken ! Appreciate it a lot 😄