support restore view

[glorv]

What problem does this PR solve?

support restore view. parcially resolve #297

What is changed and how it works?

• file routing add a new file type view-schema for view, default routing pattern is {schema}.{table}-schema-view.sql
• restore view in restoreSchema after all table schemas are restored

NOTE: Currently, we only support the view schema files exported by dumpling like tools. That is, for a table db.tbl, there must exist two schema files:

• db.tbl-schema.sql. This is for the stub table schema file.
• db.tbl-schema-view.sql. This is the actual view schema file.

If the stub table schema file does not exist, currently, lightning will report an error and exit directly.

WARN: This pr only handles the name mapping for the view name but not for the table name in the queries in the CREATE VIEW statement.

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)
• No code

Side effects

Related changes

• Need to update the documentation
• Need to be included in the release note

[glorv]

/run-all-tests

[kennytm]

Rest LGTM

[lance6716]

rest LGTM

[lichunzhu]

LGTM

waiting comment to be addressed