feat(#2849): replace hardcoded view strings with constants

[witash]

subset of #2849
Replace hardcoded view strings wtih constants to allow changing which views are in which ddocs more easily in future.

[witash]

@jkuester this is ready for review.

Mostly the changes are just find and replace the view paths with constants, mostly VIEWS.VIEW_NAME, which has the ddocs and view name combine e.g medic/contacts_by_depth.
In some cases the view name or design doc name is needed by itself, so there are helper function for that.

In some cases design ddocs are referred to by name; these are still replaced with constants e.g. DDOC_IDS.MEDIC_CLIENT; I have left these even though to actually change these references it would not be enough to just change the constant values, you would need to figure out what the relevant code is actually doing and replace it with its new equivalent. Most of these are in tests where it is checking the ddoc that should be replicated to offline clients.

although the diff is very large, the only files which changed beyond find/replace are:

• the constants file https://github.com/medic/cht-core/pull/10615/changes#diff-26d8ae4a04a0fb99b3008f481808ff1116ee8988f5a5f9c4ba52a8f92620cac9
• datasource needs explicit type defintions https://github.com/medic/cht-core/pull/10615/changes#diff-cf4fe53798a9f4f0006f50e9c1fbb7b3dbc8aa7455a19d8cab02510044d0ad5c
• cht-conf queries contacts_by_depth directly. This should be changed, and it doesn't matter currently because I haven't changed the path in this branch, but I have added api/src/middleware/deprecated-view-middleware.js to work around external code that also hardcoded view paths. https://github.com/medic/cht-core/pull/10615/changes#diff-0d229773b6cda098c6c2c5c8c244e6542f790cc4619007ce2b1e469ab2bce7c4
• datasource needed explict type defintions: https://github.com/medic/cht-core/pull/10615/changes#diff-ad1b108bfb155049f2f42a52536095c37d493a8754e4931b3540f04064fb7060
• authorization changed medic-client to REPLICATED_DDOCS (although left only medic-client in REPLICATED_DDOCS anyway) https://github.com/medic/cht-core/pull/10615/changes#diff-43bd9ea2465bdd01a3a3483e843009f50dd5cec36e8189bc1dd649c783470e28

[jkuester]

FYI, unfortunately I could not get to this PR this week. But, it is still on my TODO list, and I will review it next week! 👍

[jkuester]

Excellent uplift @witash! I particularly appreciate your care for keeping the diff clean and only containing the necessary changes!

I have gone through everything line by line and have just a few suggestions/questions. Otherwise, LGTM!

[jkuester]

Is this supposed to be here? I am not seeing the existing ddoc that this maps to... 🤔