Refactor "Options" API to be more in line with other bindings

[KrzysFR]

Looking at bindings for other languages, the transaction options are usually accessed via an "Options" property or field, so would look something like this in c#

tr.Options.Timeout = 10;
tr.Options.SetOption(FdbTransactionOption.AccessSystemKeys);

Currently, the SetOptions(...) methods are directly on the IFdbReadOnlyTransaction itself, and there is a set of extensions methods that target this interface to add the fluent versions of WithWriteAccessToSystemKeys(...) or WithNextWriteNoWriteConflictRange(..) etc..

These methods would be moved to a new IFdbTransactionOptions interface, and accessible via the tr.Options field.

Typical usage:

var results = await db.ReadWriteAsync(tr =>
{
     tr.Options.RetryLimit = 10;
     tr.Options.WithWriteAccessToSystemKeys();
     tr.Options.WithNextWriteNoWriteConflictRange();
     return tr.GetRange(....).Select(....).ToArrayAsync();
}, ct);

To keep an easy way to perform fluent configuration and query of a transaction (combined with the QueryAsync(...) helper, we would add a WithOptions(Action<IFdbTranscationOptions>) on the transaction itself, that would return the transaction instance. This would allow the caller to have the transaction handler expressed as a single expression, without the need to create a statement or block.

var res = tr.WithOptions(options => options.WithWriteAccessToSystemKeys().WithNextWriteNoWriteConflictRange())
                  .GetRange(....)
                  .Select(...)
                  .ToArrayAsync()

Pro:

• look more like other bindings
• less intellisense clutter on the transaction instance itself, with most of the options moved away into the tr.Options property
• easier to mock or provide an alternative implementation (if not using the fdb_c client library).

Drawbacks:

• is a breaking change for existing code that would call tr.WithXYZ(...) which need to change change to either tr.Options.WithXYZ(..) or use tr.WithOptions(options => options.WithXYZ()) instead.