Specify appropriate version(s) of Tendermint in a machine readable format in the repo

[james-chf]

We should specify at least one Tendermint version we are definitely compatible in our repo in a machine friendly way. Then given any commit of namada, it should be easy to see a version of tendermint that can definitely be used. This could be a simple tendermint-version file that simply has a tag/ref of the Tendermint version we are using by default, or something more advanced like a .toml that specifies the versions to be used with different feature flags.

e.g. in eth-bridge-integration

[default]
git = "https://github.com/tendermint/tendermint.git"  # default
ref = "v0.37.0-alpha.2"
cargo_default_features = true  # default
cargo_extra_features = []  # default

[abcipp]
git = "https://github.com/heliaxdev/tendermint.git"
ref = "v0.1.1-abcipp"
cargo_default_features = false
cargo_extra_features = [ "abcipp" ]

e.g. in main (until that also switches to v0.37)

[default]
git = "https://github.com/heliaxdev/tendermint.git"
ref = "v0.1.1-abcipp"

[james-chf]

From https://github.com/anoma/namada/pull/437#issue-1362022121 for eth-bridge-integration

With the abcipp feature flag enabled, test this PR with this Tendermint version: https://github.com/heliaxdev/tendermint/releases/tag/v0.1.1-abcipp

Otherwise, use this version: https://github.com/tendermint/tendermint/tree/0b58342a46b1917a40d506e48e87448dcc8b3131

[james-chf]

If we start using a stable(ish) version of Tendermint, it might just be easier to get rid of scripts/install/get_tendermint.sh altogether and point users to where to get/install Tendermint from in our README.md.

[tzemanovic]

related to https://github.com/anoma/namada/issues/525