refactor(database): move log logic into separate package

[jbrockopp]

Based off of #574, #663, #687, #692 and #721

This change continues the refactor efforts initially introduced in the above PRs.

This adds a new log package to the github.com/go-vela/server/database package.

This contains a LogService interface declaring all functions necessary for worker based interactions with the database:

server/database/log/service.go

Lines 11 to 49 in 6bf3448

	// LogService represents the Vela interface for log
	// functions with the supported Database backends.
	//
	//nolint:revive // ignore name stutter
	type LogService interface {
	// Log Data Definition Language Functions
	//
	// https://en.wikipedia.org/wiki/Data_definition_language
	// CreateLogIndexes defines a function that creates the indexes for the logs table.
	CreateLogIndexes() error
	// CreateLogTable defines a function that creates the logs table.
	CreateLogTable(string) error
	// Log Data Manipulation Language Functions
	//
	// https://en.wikipedia.org/wiki/Data_manipulation_language
	// CountLogs defines a function that gets the count of all logs.
	CountLogs() (int64, error)
	// CountLogsForBuild defines a function that gets the count of logs by build ID.
	CountLogsForBuild(*library.Build) (int64, error)
	// CreateLog defines a function that creates a new log.
	CreateLog(*library.Log) error
	// DeleteLog defines a function that deletes an existing log.
	DeleteLog(*library.Log) error
	// GetLog defines a function that gets a log by ID.
	GetLog(int64) (*library.Log, error)
	// GetLogForService defines a function that gets a log by service ID.
	GetLogForService(*library.Service) (*library.Log, error)
	// GetLogForStep defines a function that gets a log by step ID.
	GetLogForStep(*library.Step) (*library.Log, error)
	// ListLogs defines a function that gets a list of all logs.
	ListLogs() ([]*library.Log, error)
	// ListLogsForBuild defines a function that gets a list of logs by build ID.
	ListLogsForBuild(*library.Build, int, int) ([]*library.Log, int64, error)
	// UpdateLog defines a function that updates an existing log.
	UpdateLog(*library.Log) error
	}

This package also contains the engine which implements the above service interface:

server/database/log/log.go

Lines 25 to 39 in 6bf3448

	// engine represents the log functionality that implements the LogService interface.
	engine struct {
	// engine configuration settings used in log functions
	config *config
	// gorm.io/gorm database client used in log functions
	//
	// https://pkg.go.dev/gorm.io/gorm#DB
	client *gorm.DB
	// sirupsen/logrus logger used in log functions
	//
	// https://pkg.go.dev/github.com/sirupsen/logrus#Entry
	logger *logrus.Entry
	}

This engine contains no raw SQL queries for integrating with the logs table.

Instead, we leverage our DB library's (https://gorm.io/) agnostic abstraction for integrating with that table.

[codecov]

Codecov Report

Merging #722 (9ae0b99) into main (9e83ba0) will increase coverage by 0.17%.
The diff coverage is 72.93%.

@@            Coverage Diff             @@
##             main     #722      +/-   ##
==========================================
+ Coverage   54.70%   54.88%   +0.17%     
==========================================
  Files         232      244      +12     
  Lines       16392    16490      +98     
==========================================
+ Hits         8968     9050      +82     
- Misses       7024     7041      +17     
+ Partials      400      399       -1     

Impacted Files	Coverage Δ
api/log.go	0.00% <0.00%> (ø)
api/stream.go	0.00% <0.00%> (ø)
database/log/log.go	51.72% <51.72%> (ø)
database/log/create.go	66.66% <66.66%> (ø)
database/log/update.go	66.66% <66.66%> (ø)
database/sqlite/sqlite.go	66.10% <66.66%> (+1.40%)	⬆️
database/log/list.go	76.92% <76.92%> (ø)
database/log/list_build.go	80.43% <80.43%> (ø)
database/postgres/postgres.go	67.31% <81.25%> (+2.25%)	⬆️
database/log/delete.go	85.71% <85.71%> (ø)
... and 9 more

[plyr4]

LGTM thank you
I left some small nitpick comments that could be addressed separately, non-blocking