Modifying the migration extension to use its own service. (#21781)

* Adding migration service to sql migrations

* enabling auto flush log

* Adding support for env variable

* Adding TDE Migration service

* code cleanup

* updating service downloader

* Removing custom output channel

* remove unnecessary await

* Updated service version to get latest code

* Consolidate TDE into migration service

* Sync to latest main

* Update sql-migration package version

* Fix merge conflict error

* Fixing all merge conflicts

* Fixing stuff

* removing extra whitespace

* Cleaning up

---------

Co-authored-by: Akshay Mata <akma@microsoft.com>

extensions/sql-migration/config.json

@@ -0,0 +1,20 @@
+{
+	"downloadUrl": "https://github.com/Microsoft/sqltoolsservice/releases/download/{#version#}/microsoft.sqltools.migration-{#fileName#}",
+	"useDefaultLinuxRuntime": true,
+	"version": "4.5.0.12",
+	"downloadFileNames": {
+		"Windows_86": "win-x86-net6.0.zip",
+		"Windows_64": "win-x64-net6.0.zip",
+		"OSX": "osx-x64-net6.0.tar.gz",
+		"Linux": "rhel-x64-net6.0.tar.gz"
+	},
+	"installDirectory": "./migrationService/{#platform#}/{#version#}",
+	"executableFiles": ["MicrosoftSqlToolsMigration", "MicrosoftSqlToolsMigration.exe"],
+	"retry": {
+		"retries": 3,
+		"factor": 2,
+		"minTimeout": 1000,
+		"maxTimeout": 300000,
+		"randomize": false
+	}
+}