Fix parsing of quoted identifiers

[IyeOnline]

Previously a type such as

Tuple( `a.b` Int8)

would fail to parse. This would cause Client::Impl::ReadBlock to throw
an "unsupported column type" exception, even though this is a valid
ClickHouse type and supported by the library.

This fix introduces a new token type for quoted identifiers and uses this
tuples. A dedicated token type seems a semantically cleaner choice, because
formally there could be cases where Name would be accepted, but a
quoted identifier would not be allowed.

This is effectively a followup to #491

[slabko]

Hi @IyeOnline, can you please move the TupleWithQuotedFieldNamesFromServer test to a more appropriate place.
Additionally column and tuple names can have ` in their names. For example:

Tuple(`a\`b` UInt8, `a``b` UInt8)

[slabko]

@IyeOnline did you check the case with inserting data to tables with tuples like Tuple(`a.b` Int8)?

// create table test_tuple (
//      id UInt64,
//      value Tuple(`a.b` Int8)
//  )
//  engine = MergeTree
//  order by id

auto block = client.BeginInsert("INSERT INTO test_tuple VALUES");
auto col_id = block.At(0)->AsStrict<ColumnUInt64>();
auto col_tuple = block.At(1)->AsStrict<ColumnTuple>();
auto col_value = col_tuple->At(0)->AsStrict<ColumnInt8>();

col_id->Append(1);
col_id->Append(2);

col_value->Append(5);
col_value->Append(7);
block.RefreshRowCount();

client.SendInsertBlock(block);
client.EndInsert();

Gives

 DB::Exception: Syntax error (data type): failed at position 8 (.): .b Int8). Expected one of: data type, identifier

From what I can see the library does not wrap the names when sending them to the server:

[IyeOnline]

@slabko I did discover this while trying to send data to a table with a Tuple like that (with the table previously generated from a JSON schema that used such a key) With this fix, it works there.

I will look into why it doesnt work in the simple standalone case tomorrow.

[IyeOnline]

It turns out my our code actually didn't sent blocks with column names on the type as that code predates support for that. We just created the table with the named fields.