[MM-53968] Includes mattermost-plugin-api into the mono repo (#24235)

Include https://github.com/mattermost/mattermost-plugin-api into the mono repo

Co-authored-by: Jesse Hallam <jesse.hallam@gmail.com>
Co-authored-by: Michael Kochell <mjkochell@gmail.com>
Co-authored-by: Alejandro García Montoro <alejandro.garciamontoro@gmail.com>
Co-authored-by: Ben Schumacher <ben.schumacher@mattermost.com>
Co-authored-by: Alex Dovenmuehle <alex.dovenmuehle@mattermost.com>
Co-authored-by: Michael Kochell <6913320+mickmister@users.noreply.github.com>
Co-authored-by: Christopher Poile <cpoile@gmail.com>
Co-authored-by: İlker Göktuğ Öztürk <ilkergoktugozturk@gmail.com>
Co-authored-by: Shota Gvinepadze <wineson@gmail.com>
Co-authored-by: Ali Farooq <ali.farooq0@pm.me>
Co-authored-by: Maria A Nunez <maria.nunez@mattermost.com>
Co-authored-by: Daniel Espino García <larkox@gmail.com>
Co-authored-by: Christopher Speller <crspeller@gmail.com>
Co-authored-by: Alex Dovenmuehle <adovenmuehle@gmail.com>
Co-authored-by: Szymon Gibała <szymongib@gmail.com>
Co-authored-by: Lev <1187448+levb@users.noreply.github.com>
Co-authored-by: Jason Frerich <jason.frerich@mattermost.com>
Co-authored-by: Agniva De Sarker <agnivade@yahoo.co.in>
Co-authored-by: Artur M. Wolff <artur.m.wolff@gmail.com>
Co-authored-by: Madhav Hugar <16546715+madhavhugar@users.noreply.github.com>
Co-authored-by: Joe <security.joe@pm.me>
Co-authored-by: Ibrahim Serdar Acikgoz <serdaracikgoz86@gmail.com>
Co-authored-by: José Peso <trilopin@users.noreply.github.com>

server/public/pluginapi/experimental/oauther/options.go

@@ -0,0 +1,47 @@
+package oauther
+
+import "time"
+
+// Option defines each option that can be passed in the creation of the OAuther.
+// Options functions available are OAuthURL, StorePrefix, ConnectedString and OAuth2StateTimeToLive and PayloadTimeToLive.
+type Option func(*oAuther)
+
+// OAuthURL defines the URL the OAuther will use to register its endpoints.
+// Defaults to "/oauth2".
+func OAuthURL(url string) Option {
+	return func(o *oAuther) {
+		o.oAuthURL = url
+	}
+}
+
+// StorePrefix defines the prefix the OAuther will use to store information in the KVStore.
+// Defaults to "oauth_".
+func StorePrefix(prefix string) Option {
+	return func(o *oAuther) {
+		o.storePrefix = prefix
+	}
+}
+
+// ConnectedString defines the string shown to the user when the oauth flow is completed.
+// Defaults to "Successfully connected. Please close this window.".
+func ConnectedString(text string) Option {
+	return func(o *oAuther) {
+		o.connectedString = text
+	}
+}
+
+// OAuth2StateTimeToLive is the duration the states from the OAuth flow will live in the KVStore.
+// Defaults to 5 minutes.
+func OAuth2StateTimeToLive(ttl time.Duration) Option {
+	return func(o *oAuther) {
+		o.oAuth2StateTimeToLive = ttl
+	}
+}
+
+// PayloadTimeToLive is the duration the payload from the OAuth flow will live in the KVStore.
+// Defaults to 10 minutes.
+func PayloadTimeToLive(ttl time.Duration) Option {
+	return func(o *oAuther) {
+		o.payloadTimeToLive = ttl
+	}
+}