[3.x] Remove problematic unused code when formatting SQL

[derekmd]

Fixes: #919
Replaces pull request #923 as per Dries' request

Formatted SQL preview:

which should be:

Telescope's QueryWatcher always stores an empty array for query parameter bindings.

telescope/src/Watchers/QueryWatcher.php

Lines 39 to 41 in f5dee9a

	Telescope::recordQuery(IncomingEntry::make([
	'connection' => $event->connectionName,
	'bindings' => [],

This causes an issue in NPM package sql-formatter when the query has MySQL session variables referenced with an '@' character. Using the generic SQL:2011 dialect, it's treated like a named placeholder (e.g., for MS SQL Server.)

sqlFormatter.format('select @user_id := id as id from users', {params: []});
// select
//   undefined: = id as id
// from
//   users

This expects a named options parameter as if @user_id is referenced within a WHERE clause, e.g., {params: {user_id: 1}} Missing a named binding value, JavaScript undefined is instead filled in.

Excluding the params option will stop the package from attempting to fill the placeholder.

sqlFormatter.format('select @user_id := id as id from users');
// select
//   @user_id: = id as id
// from
//   users

<query-preview> cleanup

1. stop passing the bindings empty array to the .format() method since the argument is never used.
   • slotProps.entry.content.bindings returned by the API endpoint is always []
   • should that QueryWatcher.php 'bindings' => [] line also be removed? Does the JSON payload need that when PDO parameters are replaced before database insertion?
     • The change was from https://github.com/laravel/telescope/pull/706/files#diff-fa8840834f665959fe3cfa98a78adadcR42 so I think that line has been redundant since Telescope v2.1 (Sept 3, 2019)
2. Instead of referencing the generic wrapper sqlFormatter.format() public API, pull in the exact StandardSqlFormatter implementation. ES6 classes Db2Formatter, N1qlFormatter, & PlSqlFormatter are also being unnecessarily bundled into Telescope's app.js. This shrinks the production file 813kb to 796kb. There's definitely more room for perf improvement here. e.g.,
   • remove /**! NPM package comments
   • remove bootstrap.js components Telescope doesn't use like Carousel
3. remove unused Vue component props entry & batch since query data is accessed via a slotted scope.

[driesvints]

Thanks @derekmd