Transition to consistent package linking

[nkuba]

Currently, we've got multiple ways of linking packages between local repos:

1. npm link
   

   local-setup/install-keep-dashboard.sh

   Lines 37 to 51 in d29abdf

   	cd $WORKDIR/keep-core/solidity
   	npm link
   	cd $WORKDIR/keep-ecdsa/solidity
   	npm link
   	cd $WORKDIR/tbtc/solidity
   	npm link
   	printf "${LOG_START}Updating Keep Dashboard configuration...${LOG_END}"
   	cd $WORKDIR/keep-core/solidity/dashboard
   	npm link @keep-network/keep-core
   	npm link @keep-network/keep-ecdsa
   	npm link @keep-network/tbtc

2. Replacing node_modules content
   

   local-setup/install-keep-ecdsa.sh

   Lines 52 to 53 in d29abdf

   	rm -rf keep-ecdsa/solidity/node_modules/@keep-network/keep-core
   	cp -R keep-core/solidity/. keep-ecdsa/solidity/node_modules/@keep-network/keep-core

3. Replacing the dependency path in package.json
   

   local-setup/install-tbtc-dapp.sh

   Line 32 in d29abdf

   TBTC_DIR="$WORKDIR/tbtc/solidity" jq '.dependencies."@keep-network/tbtc" = env.TBTC_DIR' package.json > package.json.tmp && mv package.json.tmp package.json

We should be consistent across install scripts (preferably use the first way).

[Shadowfiend]

Notably, npm link creates a global link. That is, if someone wants a local setup working on two versions, they'd have to run the linking step when switching. Using file paths is more brittle to where the repos are with respect to each other, but it is a local link, so if you're maintaining two repo clones with distinct artifact states, as long as they're on the same chain, you can switch between them without modifying anything.

Just food for thought here---I have a mild bias for using a directory reference vs npm link for this reason, but it may not ultimately apply in the context of everything else we do.