atlasaction: refactor logic exec and change default merge message

[giautm]

• atlasaction: ensure files are in the right order
• atlasaction: refactor logic exec and change default message

[github-actions]

atlas migrate lint on atlasaction/testdata/migrations

Status	Step	Result
	No migration files detected
	ERD and visual diff generated	View Visualization
	No issues found	View Report
Read the full linting report on Atlas Cloud

[github-actions]

Atlas detected changes to the desired schema

Migration Plan (View on Atlas Cloud)

-- Create "t1" table
CREATE TABLE `t1` (
  `c1` integer NOT NULL
);
-- Create "t2" table
CREATE TABLE `t2` (
  `c1` integer NOT NULL
);
-- Create "t3" table
CREATE TABLE `t3` (
  `c1` integer NOT NULL,
  `c2` integer NOT NULL
);

Atlas lint results

Status	Step	Result
	Detect schema changes	3 new statements detected
	No issues found

---

📝 Steps to edit this migration plan

1. Run the following command to pull the generated plan to your local workstation:

atlas schema plan pull --url "atlas://atlas-action/plans/pr-366-R1cGcSfo" > pr-366-R1cGcSfo.plan.hcl

2. Open pr-366-R1cGcSfo in your editor and modify it as needed. Note that the result of the plan should align
the database with the desired state. Otherwise, Atlas will report a schema drift.

3. Push the updated plan to the registry using the following command:

atlas schema plan push --pending --file pr-366-R1cGcSfo.plan.hcl

4. Re-trigger the schema/plan action to update this comment:

gh run rerun 14089735265

[giautm]

testdata/need_rebase: rebase migration files

This is our format for commits

[giautm]

We need ensure this order correctly, if not. It will causes incident on the user database.

[ronenlu]

Testscript King