knex.dropTable() errors on Oracle when .withSchema()

[code-ape]

Environment

Knex version: 0.95.8
Database + version: Oracle 18c (@atiertant)
OS: Ubuntu Linux

Bug

1. Explain what kind of behaviour you are getting and how you think it should do

When attempting to delete a table for a given schema (called a "user" in Oracle) then the migration fails with an error.

2. Error message

-- indent formatted by issue filer for easier reading
drop table "my_table";
begin
  execute immediate 'drop sequence "my_table"';
  exception when others then if sqlcode != -2289 then raise;
  end if;
end;

-- Error: drop table "my_table" - ORA-00942: table or view does not exist

3. Reduced test code, for example in https://npm.runkit.com/knex or if it needs real
   database connection to MySQL or PostgreSQL, then single file example which initializes
   needed data and demonstrates the problem.

// Create schema / user
const sanitizedRaw = knex.raw(`CREATE USER ?? IDENTIFIED BY ??`, [schemaName, schemaName]).toQuery()
await knex.schema.raw(sanitizedRaw)
// Create table
await knex.schema.withSchema('my_schema').createTable('my_table', (table) => {
  table.increments('id').primary()
})
// Drop table
knex.schema.withSchema('my_schema').dropTable('my_table')

[code-ape]

It appears this can be resolved by fixing the following functions in knex/lib/dialects/oracle/schema/oracle-compiler.js:

1. dropTable needs to use schema name if it exists (this.schema).
2. dropTableIfExists needs to use schema name if it exists (this.schema).
3. dropSequenceIfExists needs to use schema name if it exists (this.schema).

Example code:

  dropSequenceIfExists(sequenceName) {
    const prefix = this.schema ? `"${this.schema}".` : "";
    this.pushQuery(
      utils.wrapSqlWithCatch(
        `drop sequence ${prefix}${this.formatter.wrap(sequenceName)}`,
        -2289
      )
    );
  }

[kibertoad]

Released in 0.95.9