GPKG/SQlite: Error when running ExecuteSQL() with a spatial filter on an empty layer

[Even Rouault]

If running ExecuteSQL() with a select that returns 0 row and has a spatial filter, a "Invalid geometry field index : 0" error is returned

[Even Rouault]

In 35279:

GPKG/SQlite: do not emit error when running ExecuteSQL() with a spatial filter on an empty layer (fixes #6639)

[Even Rouault]

In 35280:

GPKG/SQlite: do not emit error when running ExecuteSQL() with a spatial filter on an empty layer (fixes #6639)

[Even Rouault]

In 35281:

GPKG/SQlite: do not emit error when running ExecuteSQL() with a spatial filter on an empty layer (fixes #6639)

[Even Rouault]

In 35282:

GPKG/SQlite: do not emit error when running ExecuteSQL() with a spatial filter on an empty layer (fixes #6639)