POS-15 Remove building Heimdall for each chain

[igorcrevar]

a new Heimdall binary gets built for each chain using Makefile and including some config parameters at build time.

Build is done with:

https://github.com/maticnetwork/heimdall#usage

Heimdall runs this function to generate the heimdall_params.go:

https://github.com/maticnetwork/heimdall/blob/master/Makefile#L34

https://github.com/maticnetwork/heimdall/blob/master/helper/heimdall-params.template.go

It is only used to set this param for the client:

https://github.com/maticnetwork/heimdall/blob/master/helper/heimdall-params.template.go#L20

The goal is to move those parameters to Heimdall and use a flag:

$ heimdall --chain=[mumbai,mainnet,local]

to run the binary for each chain.

Internally, depending on the chain set the value of the NewSelectionAlgoHeight value.

Proposal:
There are multiple copying of chain toml files (during build and during init), maybe we should hard-code NewSelectionAlgoHeights and create files (or just one toml) during init phase

[vcastellm]

LGTM

[igorcrevar]

I forgot to edit README.md and to remove one line from .gitignore and makefile referencing heimdall-params.go
Also I have added $ heimdalld init between install and start part of readme, it was not there before. Please review these changes also

[ferranbt]

LGTM! I will add also Arpit to review since he is the one with the most experience with Heimdall and also so that he can be on the loop.

[codecov-commenter]

Codecov Report

Merging #738 (f8b5b91) into master (1cb8737) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #738   +/-   ##
=======================================
  Coverage   72.88%   72.88%           
=======================================
  Files          49       49           
  Lines        3507     3507           
=======================================
  Hits         2556     2556           
  Misses        723      723           
  Partials      228      228           

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[ferranbt]

As commented over Slack, please change the target branch for the PR to v2 and we can merge it.