Proposal: [Discuss] [Core] Remove custom Package manager from osd-pm

[mihirsoni]

As of now the Dashboards project entirely depends on custom build logic inside osd-pm The main purpose was to support OSS v/s non OSS development and distribution. This adds up lots of extra overheads over custom build system maintenance.

Describe the solution you'd like
This issue is to provide idea / PoC / designs to use more OSS and community friendly tool such as lerna, yarn workspace Or latest release of Npm workspace.

Note: This issues doesn't intent any immediate changes or ongoing implementation but more on to collect idea and how can we improve overall developer experience with community friendly tooling.

[ahopp]

@mihirsoni Where are we at with this?

[joshuarrrr]

It would be helpful to have some sense of our intended direction here, particularly because the osd-pm README contains some text that may be misleading or at odds with our plans.

This issue description is also a bit confusing because osd-pm claims to actually use yarn workspaces under the hood:

OpenSearch-Dashboards/packages/osd-pm/README.md

Lines 57 to 58 in b19c171

	For packages that are referenced within the OpenSearch Dashboards repo itself, we are leveraging
	Yarn's workspaces feature. This allows yarn to optimize node_modules within

In addition, the README contains lots of information about the other tools suggested here and why this approach was chosen:

OpenSearch-Dashboards/packages/osd-pm/README.md

Lines 200 to 212 in b19c171

	## Technical decisions
	### Why our own tool?
	While exploring the approach to static dependencies we built PoCs using npm 5
	(which symlinks packages using [`file:` dependencies][npm5-file]), [Yarn
	workspaces][yarn-workspaces], Yarn (using `link:` dependencies), and
	[Lerna][lerna].
	In the end we decided to build our own tool, based on Yarn, and `link:`
	dependencies, and workspaces. This gave us the control we wanted, and it fits
	nicely into our context (e.g. where publishing to npm isn't necessarily
	something we want to do).