GH-35107: [FlightSQL]: Use uint8 to refer to 8 bit unsigned integer…

…s rather than `uint1` (#35108)

### Rationale for this change

The spec is inconsistent -- see details on #35107

### What changes are included in this PR?

Use `uint8` to refer to 8 bit unsigned integers rather than `uint1`

### Are these changes tested?
No, they are comment only changed

### Are there any user-facing changes?

This clarifies a small corner case in the document
* Closes: #35107

Authored-by: Andrew Lamb <andrew@nerdnetworks.org>
Signed-off-by: Andrew Lamb <andrew@nerdnetworks.org>

format/FlightSql.proto

@@ -1324,8 +1324,8 @@ enum UpdateDeleteRules {
  *  key_sequence: int not null,
  *  fk_key_name: utf8,
  *  pk_key_name: utf8,
- *  update_rule: uint1 not null,
- *  delete_rule: uint1 not null
+ *  update_rule: uint8 not null,
+ *  delete_rule: uint8 not null
  * >
  * The returned data should be ordered by fk_catalog_name, fk_db_schema_name, fk_table_name, fk_key_name, then key_sequence.
  * update_rule and delete_rule returns a byte that is equivalent to actions declared on UpdateDeleteRules enum.
@@ -1370,8 +1370,8 @@ message CommandGetExportedKeys {
  *  key_sequence: int not null,
  *  fk_key_name: utf8,
  *  pk_key_name: utf8,
- *  update_rule: uint1 not null,
- *  delete_rule: uint1 not null
+ *  update_rule: uint8 not null,
+ *  delete_rule: uint8 not null
  * >
  * The returned data should be ordered by pk_catalog_name, pk_db_schema_name, pk_table_name, pk_key_name, then key_sequence.
  * update_rule and delete_rule returns a byte that is equivalent to actions:
@@ -1423,8 +1423,8 @@ message CommandGetImportedKeys {
  *  key_sequence: int not null,
  *  fk_key_name: utf8,
  *  pk_key_name: utf8,
- *  update_rule: uint1 not null,
- *  delete_rule: uint1 not null
+ *  update_rule: uint8 not null,
+ *  delete_rule: uint8 not null
  * >
  * The returned data should be ordered by pk_catalog_name, pk_db_schema_name, pk_table_name, pk_key_name, then key_sequence.
  * update_rule and delete_rule returns a byte that is equivalent to actions: